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Screening and treatment of posttraumatic stress disorder in patients with substance usedisorders
van Dam, D.
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SCREENING AND TREATMENT OF
POSTTRAUMATIC STRESS
DISORDER IN PATIENTS WITH
SUBSTANCE USE DISORDERS
Debora van DamDebora van DamDebora van DamDebora van Dam
Uitnodiging
Voor het bijwonen van deopenbare verdedigingvan mijn proefschrift:
Screening and Treatmentof Posttraumatic Stress
Disorder in Patients with Substance Use Disorders
Op 12 december 2014om 12.00 uur in de
Agnietenkapel van deUniversiteit van Amsterdam,Oudezijds Voorburgwal 231
Amsterdam.
Receptie ter plaatsena afl oop van de promotie.
Debora van [email protected]
Paranimfen:Reineke KunzeLiselotte Boeve
1_Untitled-2.job1_Proefschrift Debora van Dam.job
SCREENING AND TREATMENT OF
POSTTRAUMATIC STRESS
DISORDER IN PATIENTS WITH
SUBSTANCE USE DISORDERS
2_Untitled-2.job2_Proefschrift Debora van Dam.job
© Debora van Dam, 2014 Cover design: Haveka Printed by: Haveka
3_Untitled-2.job3_Proefschrift Debora van Dam.job
SCREENING AND TREATMENT OF
POSTTRAUMATIC STRESS
DISORDER IN PATIENTS WITH
SUBSTANCE USE DISORDERS
ACADEMISCH PROEFSCHRIFT
ter verkrijging van de graad van doctor aan de Universiteit van Amsterdam op gezag van de Rector Magnificus
prof. dr. D.C. van den Boom ten overstaan van een door het college voor promoties
ingestelde commissie, in het openbaar te verdedigen in de Agnietenkapel
op vrijdag 12 december 2014, te 12:00 uur
door
Debora van Dam
geboren te Amsterdam
4_Untitled-2.job4_Proefschrift Debora van Dam.job
Promotiecommissie Promotor: Prof. dr. P.M.G. Emmelkamp Co-promotoren Prof. dr. T.W.A. Ehring
Dr. E. Vedel
Overige Leden: Prof. dr. R.W.H.J. Wiers
Prof. dr. A.R. Arntz Prof. dr. A. van Minnen Prof. dr. A.E. Goudriaan Prof. dr. M. Olff Dr. A.A.P. van Emmerik
Faculteit der Maatschappij en Gedragswetenschappen
5_Untitled-2.job5_Proefschrift Debora van Dam.job
CContents Chapter 1 General introduction 6
Chapter 2 Validation of the PC-PTSD screening questionnaire in civilian substance 20
use disorder patients
Chapter 3 Screening for posttraumatic stress disorder in civilian substance use disorder 44
patients: cross-validation of the Jellinek-PTSD screening questionnaire
Chapter 4 Psychological treatments for concurrent posttraumatic stress disorder and 61
substance use disorder: a systematic review
Chapter 5 The effectiveness of integrated trauma-focused treatment for concurrent 98
posttraumatic stress disorder and substance use disorder: a randomized
controlled trial
Chapter 6 Trauma-focused treatment for posttraumatic stress disorder combined with 131
CBT for severe substance use disorder: a randomized controlled trial
Chapter 7 General discussion 159
Appendix A The Jellinek-PTSD screening questionnaire 178
Summary 179
Nederlandse samenvatting [Summary in Dutch] 182
Dankwoord [Acknowledgements] 185
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6
CChapter 1
General introduction
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7
Introduction
The subject of this thesis is the screening and psychological treatment of posttraumatic
stress disorder (PTSD) in patients with substance use disorders (SUDs). This expanding research
area is of great clinical importance, as the prevalence of concurrent PTSD and SUD is high
(Gielen, Havermans, Tekelenburg, & Jansen, 2012; Harrington & Newman, 2007; Kimerling,
Trafton, & Nguyen, 2006; Mills, Teesson, Ross, & Peters, 2006), and PTSD appears to have a
negative influence on SUD treatment outcomes (Back, Brady, Sonne, & Verduin, 2006;
Ouimette, Brown, & Najavits, 1998).
First, the diagnostic criteria of PTSD and SUD are described. Second, the prevalence of
concurrent PTSD and SUD is discussed, as well as the current practice with respect to screening
of PTSD within substance abuse treatment centers. This will be followed by theories and
empirical findings that account for the functional relationship between both disorders, addressing
the consequences of this relationship for the treatment of comorbid PTSD and SUD. Finally, the
rationale of the PTSD treatment studied in this thesis is considered.
Posttraumatic stress disorder (PTSD)
In this thesis posttraumatic stress disorder (PTSD) is defined according to the fourth
editon of the Diagnostic and Statistical manual of Mental disorders (DSM-IV, American
Psychiatric Association [APA], 1994). According to the DSM-IV, PTSD is induced by one or
several traumatic experiences. Patients with PTSD have experienced, witnessed, or were
confronted with actual or threatened death or serious injury, or a threat to the physical integrity of
self or others. During the trauma, the person's response involved intense fear, helplessness or
horror. Full-blown PTSD is diagnosed if patients suffer from the symptom clusters re-
experiencing, avoidance and increased arousal after a traumatic event. Patients have to meet at
least one of the five re-experiencing symptoms, three of the seven avoidance symptoms and two
of the five arousal symptoms. In this thesis partial PTSD is defined as meeting symptom criteria
for the re-experiencing cluster and for the avoidance/numbing cluster or the hyperarousal cluster
(Blanchard, Hickling, Taylor, Loos, & Gerardi, 1994). The fifth edition of the DSM has been
published in 2013 (DSM-5, APA, 2013). criteria for PTSD comprise a history of exposure to
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8
a traumatic event, followed by four symptom clusters: intrusion, avoidance, negative alterations
in cognitions and mood, and alterations in arousal and reactivity.
Substance use disorder (SUD)
In this thesis, substance use disorder is diagnosed according to the DSM-IV. It refers to a
maladaptive pattern of substance use leading to clinically significant impairment or distress,
occurring within a 12-month period. A distinction is made between substance abuse and
substance dependence. Substance dependence is characterised by a pattern of repeated self-
administration that can result in tolerance, withdrawal, and compulsive alcohol or drug taking
behaviour. A diagnosis for substance abuse is given if patients experience recurrent and
significant adverse consequences related to the repeated use of substances. In DSM-5 the
categories of substance abuse and substance dependence are combined into a single disorder
measured on a continuum from mild to severe.
Prevalence of PTSD among SUD patients
Community-based studies indicate a lifetime prevalence for PTSD of approximately 7%
in the Netherlands (De Vries & Olff, 2009). There is a lack of epidemiological studies
investigating the prevalence of PTSD among SUD patients, which makes it difficult to compare
the percentages found within the general population with those found in SUD research samples.
However, a recent study addressing this issue, showed a higher prevalence of PTSD among SUD
patients (37%) compared to patients without SUD (10%) (Gielen et al., 2012). These findings are
in line with other data suggesting that the prevalence of PTSD among SUD patients is relatively
high (ranging from 20 to 41%) (Harrington & Newman, 2007; Kimerling et al., 2006; Ouimette,
Goodwin & Brown, 2006). Also, in accordance with findings for the general population (De
Vries & Olff, 2009) women have shown higher rates of PTSD than men within a sample of SUD
patients (Hyman, Garcia, Kemp, Mazure, & Sinha, 2005).
Despite of the high prevalence of PTSD among SUD patients, PTSD symptoms are often
not reported during SUD treatment, unless patients are asked specifically about traumatic events
or PTSD symptoms (Gielen et al., 2012; Kimerling et al., 2006). Perhaps this is a logical
consequence of the disorder itself as the persistent avoidance of stimuli associated with the
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9
trauma is one of its diagnostic criteria. Another explanation may be that patients themselves do
not perceive the relevance of mentioning PTSD symptoms in the context of their SUD treatment.
Without screening for PTSD, approximately seventy-five percent of the patients with concurrent
PTSD and SUD do not mention their PTSD symptoms during treatment (Kimerling et al., 2006).
This means that PTSD symptoms remain undetected for three out of every four SUD patients. As
this patient group is more severe, it is clinically relevant to recognize these patients. Therefore
systematic screening of PTSD among SUD patients is recommended (Gielen et al., 2012).
Screening for PTSD among SUD patients
It has been suggested that treatment prognoses for patients with concurrent PTSD and
SUD can be improved by new treatment interventions suited to the specific needs of this patient
group (Donovan, Padin-Rivera, & Kowaliw, 2001; Driessen et al., 2008; McGovern et al., 2009;
Najavits, 2007; Rash, Coffey, Baschnagel, Drobes, & Saladin, 2008). Effective detection of these
patients is a necessary first step. As mentioned above, PTSD symptoms are not recognized in a
large group of SUD patients (Gielen et al., 2012; Kimerling et al., 2006). The Structured Clinical
Interview for DSM-IV axis I Disorders (SCID-I) (First, Spitzer, Gibbon, & Williams, 1996; Van
Groenestijn, Akkerhuis, Kupka, Schneider, & Nolen, 1999), and the Clinician-Administered
PTSD Scale (CAPS) (Blake et al., 1990) are generally considered to be the gold standard to
formally assess the presence of PTSD. However, it would neither be efficient nor patient-friendly
to conduct an extensive diagnostic PTSD interview to every SUD patient. A better alternative is
to use a PTSD screening questionnaire. Then, only the patients scoring above the cutoff of the
PTSD screening questionnaire can be allocated for further assessment. Preferably, a screener
identifies patients with or without PTSD as precisely as possible, as is mirrored in a high
sensitivity (the percentage of patients with a positive diagnosis, scoring positive on the screener)
and a high specificity (the percentage of patients with a negative diagnosis, scoring negative on
the screener). Another important criterion for PTSD screeners is its user-friendliness (Brewin,
2005). Preferably, it should take little time and effort to be filled out by patients, and to be
interpreted by therapists (Brewin, 2005). User-friendliness is especially important for the use
among SUD patients, as in many cases the screener will be offered before treatment allocation.
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This means that a substantial number of SUD patients have to fill out the screener, during the
intake phase of treatment, when they may be still under the influence of substances.
Considering the former remarks about important screener characteristics, the Primary
Care posttraumatic stress disorder screen (PC-PTSD) (Prins et al., 2003), appears to meet the
criteria of good diagnostic efficiency and user-friendliness. The PC-PTSD was developed to
detect PTSD among veterans of the United States army. I
evaluated within Veteran Affairs (VA) substance abuse treatment centers (Kimerling et al.,
2006). The PC-PTSD showed a high sensitivity (.91), and a high specificity (.80) for the VA
SUD patient group (Kimerling et al., 2006). This implicates that the screener will detect 91 out of
100 PTSD cases within a group of VA SUD patients. In a group of 100 VA SUD patients with no
diagnosis for PTSD, the PC-PTSD will properly identify 80 out of 100 patients as having no
PTSD. The PC-PTSD includes four yes-or-no items that refer to the PTSD symptom clusters re-
experiencing, avoidance, numbing, and increased arousal. Based on findings for the VA SUD
sample, it seems a promising instrument to detect PTSD among SUD patients. In the current
thesis, we have investigated and cross-validated the qualities of the PC-PTSD as well as a
modified version of the screener within a sample of civilian SUD patients.
The functional relationship of PTSD and SUD
There are theoretical as well as empirical grounds to assume that PTSD and SUD are
highly intertwined and reciprocally related (Stewart & Conrod, 2003). There are indications that
in most cases, PTSD precedes SUD (Stewart & Conrod, 2003). This lends support to the self-
surpress and avoid painful and disturbing PTSD symptoms (Khantzian, 1985; Stewart & Conrod,
2003). This hypothesized process of self-medication where PTSD leads to SUD has been
recognized by patients (Back, Brady, Sonne, & Verduin, 2006; Brown, Stout, & Gannon-Rowley,
1998), and has been affirmed by experimental research (Coffey et al., 2002; Saladin et al., 2003).
An inverse relationship between PTSD and SUD has also been suggested. The high risk
hypothesis (Hien, Cohen, & Campbell, 2005) proposes that substance abuse exposes individuals
to more high risk situations where traumas are lurking (Hien et al., 2005). It is also possible that
substance abuse maintains PTSD symptoms by interfering with trauma extinction (Stewart &
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Conrod, 2003), or that it maintains emotional numbing in PTSD (Stewart, 1996). Moreover,
substance use and/or withdrawal can lead to physical symptoms mirroring physical symptoms of
hyperarousal experienced during trauma, which may evoke traumatic memories (Stewart &
Conrod, 2003). Consequently, patients with concurrent PTSD and SUD may end up in a vicious
circle: PTSD can lead to substance abuse by the process of self-medication, SUD possibly
exposes patients to high risk situations that increase the probability of experiencing trauma, SUD
may maintain PTSD, and SUD may trigger PTSD symptoms by withdrawal symptoms (Stewart
& Conrod, 2003) (see Figure 1).
Figure 1. Vicious circle of PTSD and substance abuse
The treatment of concurrent PTSD and SUD
In clinical practice it is common to treat PTSD and SUD sequentially. That is, SUD is
treated first, and after the successful completion of this treatment, a patient is referred to PTSD
treatment (Henslee & Coffey, 2010). It is possible that this is not the most effective approach for
this patient group (Najavits, 2007). The assumed relationship between PTSD and SUD, as
described above, predicts an initial, but temporary, increase of PTSD symptoms when individuals
stop using substances to self-medicate. Consequently, this could make patients more vulnerable
for relapse in the beginning of SUD treatment, as in the initial phase of SUD treatment they have
not yet experienced the possible long term benefits of abstinence. Therefore, the current
sequential approach seems predestined to fail in an early phase. Several authors have suggested
that treatment may be more beneficial if both SUD and PTSD are addressed within the same time
PTSD Substance abuse
Withdrawal
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frame (Bradizza, Stasiewicz, & Paas, 2006; Donovan et al., 2001; Ford, Russo, & Mallon, 2007;
McGovern et al., 2009; Najavits, 2007). In the current thesis, we have studied the effectiveness of
PTSD treatment during SUD treatment. The term effectiveness, instead of efficacy, is used to
indicate that the applicability of the research findings to real-life practice is an important focus of
this thesis (see also the general discussion) (Kraemer, 2000).
Generally, PTSD treatments can be divided into non-trauma-focused and trauma-focused
interventions. Described briefly, non-trauma-focused interventions focus on the improvement of
coping skills to manage trauma symptoms, while trauma-focused treatments focus on
detailed memories of the traumatic event and its meaning (National Collaborating Centre for
Mental Health, 2005; Powers, Halpern, Ferenschak, Gillihan, & Foa, 2010). Some researchers
and clinicians hesitate to implement trauma-focused treatment to SUD patients as it could be too
stressful for this vulnerable patient group, triggering relapse, treatment dropout and other adverse
events (Najavits, 2004; Pitman et al., 1991). However, trauma-focused treatment is the first-
choice evidence-based treatment for PTSD (Institute of Medicine, 2008). In the clinical studies of
this thesis the effectiveness of Structured Writing Therapy (SWT) (Van Emmerik, Kamphuis, &
Emmelkamp, 2008), a trauma-focused PTSD treatment, was investigated among SUD patients.
The intervention for SUD was evidence-based cognitive behavioral treatment (CBT)
(Emmelkamp & Vedel, 2006).
Structured Writing Therapy (SWT)
SWT is a trauma-focused PTSD treatment that utilizes specific writing assignments to
reprocess traumatic events. SWT has been described as an alternative set of procedures for
imaginal exposure and cognitive restructuring (Van Emmerik, 2004). The therapeutic model
originates from Lange, Van de Ven, Schrieken, & Emmelkamp (2001), and has been applied
online (Interapy) (Lange et al., 2003; Lange et al., 2001), and face-to-face (Van Emmerik et al.,
2008). SWT incorporates three phases; self-confrontation, cognitive reappraisal, and sharing and
farewell. The self-confrontation phase focuses on the exposure to painful traumatic memories in
order to ascertain extinction of the trauma. Exposure is established by detailed writings of the
patient about the most traumatic event(s) he or she had experienced. The traumatic event is
described in the first-person, as if it happens presently, including the reactions, thoughts and
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emotions that were also present during the trauma. Participants are instructed to write without
restraints and not to worry about style, spelling, grammar or chronology. In the phase of cognitive
reappraisal, a patient is stimulated to perceive the event from another perspective. He or she is
instructed to write a supportive letter of advice to someone close or imaginary, who (presumably)
has experienced the same event. The letter has to encompass useful suggestions of how to
perceive and interpret the traumatic experience, and how to live with its consequences. The
sharing and farewell ritual aims to accomplish symbolic closure of the traumatic event. A final
letter is written, where the patient contemplates the trauma, and its impact on life. The underlying
rationale is the proven importance of sharing traumatic experiences (Schoutrop, 2000), although
this final letter is not necessarily sent to the addressed person.
Results from several studies support the effectiveness of SWT in the treatment of PTSD
(Lange et al., 2003; Lange et al., 2001; Van Emmerik et al., 2008). SWT has been compared to
trauma-focused cognitive behavioral treatment (CBT) for PTSD including psycho-education,
prolonged imaginal exposure, exposure in vivo, and cognitive restructuring. SWT proved to be
equally effective for PTSD as CBT for PTSD (Van Emmerik et al., 2008), as both treatment led
tot improvements on intrusion and avoidance symptoms.
In the current thesis, we have investigated the effectiveness of combined treatment for
PTSD and SUD in two clinical trials. In one trial, the SWT protocol was integrated with an
individual outpatient CBT treatment for SUD, and in the other trial SWT was added on to an
intensive group CBT treatment program for severe SUD patients.
Present thesis
The present thesis includes four studies and a systematic review regarding the screening
and treatment of PTSD among SUD patients. The first study is described in Chapter 2, and
focuses on the validation of the PC-PTSD screening questionnaire for PTSD in patients attending
treatment for substance use. The research started in 2007. Previous research had shown there was
a large, invisible, and vulnerable group of patients with concurrent PTSD and SUD within
substance abuse treatment centers, and that active screening improved the detection of those
patients considerably (Kimerling et al., 2006). At that time, there were only four instruments
investigated within a sample of SUD patients (Coffey, Dansky, Falsetti, Saladin, & Brady, 1998;
Harrington & Newman, 2007; Kimerling et al., 2006). One of those was the PC-PTSD that stuck
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out because of its good diagnostic qualities and user-friendliness. As the screener had exclusively
been investigated within a VA setting, we decided to validate its qualities within a civilian group
of SUD patients. We also investigated whether it was possible to enhance its performances. In
this study, the diagnostic efficiency of the screener was compared to an extended eight item
version of the PC-PTSD and the Posttraumatic Diagnostic Scale (PDS) (Foa, Cashman, Jaycox,
& Perry, 1997).
The third chapter covers an extension of the first research where the diagnostic efficiency
of a modified version of the PC-PTSD was cross-validated. This modified version of the PC-
PTSD will be referred to as the Jellinek-PTSD (J-PTSD) screening questionnaire.
Chapter 4 gives an overview of research into psychological treatments for concurrent
PTSD and SUD. It focuses on the effectiveness of combined treatments for both disorders
compared to treatments addressing one of the disorders alone. In addition, a distinction is made
between trauma-focused versus non-trauma-focused therapies for concurrent PTSD and SUD.
Chapter 5 presents an RCT investigating the effectiveness of an integrated trauma-focused
treatment for concurrent PTSD and SUD. In this study, SWT was integrated with individual CBT
for SUD (CBT/SUD + SWT), and compared to CBT for SUD alone (CBT/SUD). The study
started in 2008, and was carried out among outpatients from the Jellinek, a large substance abuse
treatment center in Amsterdam, The Netherlands. Until then, only four RCTs had been published
on this topic (Coffey, Stasiewicz, Hughes, & Brimo, 2006; Cohen & Hien, 2006; Hien, Cohen,
Miele, Litt, & Capstick, 2004; Najavits, Gallop, & Weiss, 2006; Triffleman, 2000), and only one
had investigated the effectiveness of trauma-focused treatment (Coffey et al., 2006). Promising
results of the Coffey (2006) study, together with the recommendation of treating PTSD with
trauma-focused treatment (Brewin, 2005), warranted further research.
During the recruitment of the outpatient study, there was a strong appeal to extend the
research to more severe patients allocated to daycare or clinical care. Instead of excluding these
patients for further research, we decided to perform another RCT within this group, which is
presented in Chapter 6. In this study, SWT was added on to treatment as usual (TAU) and
compared to TAU alone. TAU comprised an intensive cognitive behavioral inpatient or day
group treatment for SUD. The final chapter encompasses the general discussion.
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McGovern, M. P., Lambert-Harris, C., Acquilano, S., Xie, H. Y., Alterman, A. I., & Weiss, R. D.
(2009). A cognitive behavioral therapy for co-occurring substance use and posttraumatic
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disorders: Findings from the Australian National Survey of Mental Health and Well-
Being. American Journal of Psychiatry, 163, 652-658.
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43-62.
Najavits, L. M. (2007). Seeking safety: An evidence-based model for substance abuse and
trauma/PTSD. In K. A. Witkiewitz & G. A. Marlatt (Eds.), Therapists' Guide to
Evidence-Based Relapse Prevention: Practical Resources for the Mental Health
Professional (pp. 141 167). San Diego, USA: Elsevier Press.
Najavits, L. M., Gallop, R. J., & Weiss, R. D. (2006). Seeking safety therapy for adolescent girls
with PTSD and substance use disorder: a randomized controlled trial. Journal of
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National Collaborating Centre for Mental Health. (2005). Clinical Guideline 26. Post-Traumatic
Stress Disorder: The Management of PTSD in Adults and Children in Primary and
Secondary Care. London, UK: National Institute for Clinical Excellence.
Ouimette, P., Goodwin, E., & Brown, P. J. (2006). Health and well being of substance use
disorder patients with and without posttraumatic stress disorder. Addictive Behaviors, 31,
1415-1423.
Ouimette, P., Brown, P. J., & Najavits, L. M. (1998). Course and treatment of patients with both
substance use and posttraumatic stress disorders. Addictive Behaviors, 23, 785-795.
Pitman, R. K., Altman, B., Greenwald, E., Longpre, R. E., Macklin, M. L., Poiré, R. E., et al.
(1991). Psychiatric complications during flooding therapy for posttraumatic stress
disorder. Journal of Clinical Psychiatry, 52, 17-20.
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analytic review of prolonged exposure for posttraumatic stress disorder. Clinical
Psychology Review, 30, 635-641.
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Prins, A., Ouimette, P., Kimerling, R., Cameron, R. P., Hugelshofer, D. S., Shaw-Hegwer, J., et
al. (2003). The primary care PTSD screen (PC-PTSD): development and operating
characteristics. Primary Care Psychiatry, 9, 9-14.
Rash, C. J., Coffey, S. F., Baschnagel, J. S., Drobes, D. J., & Saladin, M. E. (2008). Psychometric
properties of the IES-R in traumatized substance dependent individuals with and without
PTSD. Addictive Behaviors, 33, 1039-1047.
Saladin, M. E., Drobes, D. J., Coffey, S. F., Dansky, B. D., Brady, K. T., & Kilpatrick, D. G.
(2003). PTSD symptom severity as a predictor of cue-elicited drug craving in victims of
violent crime. Addictive Behaviors, 28, 1611-1629.
Schoutrop, M. J. A. (2000). Structured writing and processing traumatic events. Amsterdam, The
Netherlands: University of Amsterdam.
Stewart, S. H. (1996). Alcohol abuse in individuals exposed to trauma: a critical review.
Psychological Bulletin, 120, 83-112.
Stewart, S. H., & Conrod, P. J. (2003). Psychosocial models of functional associations between
posttraumatic stress disorder and substance use disorder. In P. Ouimette & P. J. Brown
(Eds.), Trauma and substance abuse: Causes, consequences, and treatment of comorbid
disorders (pp. 29-55). Washington DC, USA: American Psychological Association.
Triffleman, E. (2000). Gender differences in a controlled pilot study of psychosocial treatments
in substance dependent patients with post-traumatic stress disorder: Design considerations
and outcomes. Alcoholism Treatment Quarterly, 18, 113-126.
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disorder. Amsterdam, The Netherlands: University of Amsterdam.
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Disorder and Posttraumatic Stress Disorder with Cognitive Behavioral Therapy or
Structured Writing Therapy: A Randomized Controlled Trial. Psychotherapy and
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(1999). Gestructureerd klinisch interview voor de vaststelling van DSM-IV as-I
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I)]. Lisse, The Netherlands: Swets & Zeitlinger.
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CChapter 2
Validation of the PC-PTSD screening questionnaire in
civilian substance use disorder patients
Van Dam, D., Ehring, T., Vedel, E., & Emmelkamp, P. M. G. (2010). Validation of the Primary Care Posttraumatic
Stress Disorder screening questionnaire (PC-PTSD) in civilian substance use disorder patients. Journal of Substance
Abuse Treatment, 39, 105-113.
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Abstract
This study aimed to cross-validate and extend earlier findings regarding the diagnostic
efficiency of the four-item Primary Care posttraumatic stress disorder screen (PC-PTSD) as a
screening questionnaire for posttraumatic stress disorder (PTSD) among civilian patients with
substance use disorder (SUD). The PC-PTSD was originally developed in a Veteran Affairs
primary care setting and has been widely used in the U.S. army. The diagnostic efficiency of the
screener was compared to those of an extended eight-item version of the PC-PTSD and the
Posttraumatic Diagnostic Scale (PDS). The sample consisted of 142 participants with SUD and
most of the participants (89%) were still using substances in the month preceding the assessment.
Results showed a high sensitivity (.86) and moderate specificity (.57) for the PC-PTSD when
using a cutoff score of 2. The diagnostic efficiency of the PC-PTSD was equivalent to the
extended eight-item version and the 17-item PDS. Results suggest that the original PC-PTSD is a
useful screening instrument for PTSD within a civilian SUD population. These findings have
important clinical implications because screening for PTSD among patients with SUD is crucial
to ascertain appropriate treatment allocation.
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Introduction
Posttraumatic stress disorder (PTSD) has been found to be a highly prevalent comorbid
condition among patients with substance use disorder (SUD). However, the exact prevalence
estimates reported in the literature vary markedly, ranging from 11% to 41%. This variation may
at least partly be due to differences in assessment methods (e.g., questionnaire measures vs.
diagnostic interviews) and differing population characteristics (Bonin, Norton, Asmundson,
Dicurzio, & Pidlubney, 2000; Cacciola, Koppenhaver, Alterman, & McKay, 2009; Dansky,
Saladin, Coffey, & Brady, 1997; Dragan & Lis-Turlejska, 2007; Driessen et al., 2008; Harrington
& Newman, 2007; Kimerling, Trafton, & Nguyen, 2006; Najavits, 2003; Najavits, et al. 1998;
Ouimette, Goodwin, & Brown, 2006; Reynolds et al., 2005; Triffleman, 1995). The high
comorbidity between SUD and PTSD has important clinical implications. Compared to
individuals with either disorder alone, patients with comorbid SUD and PTSD show more severe
symptoms and worse treatment outcome (Back et al., 2000; Brown & Wolfe, 1994; Najavits,
Weiss & Shaw, 1999; Ouimette, Brown & Najavits, 1998). It has been suggested that the
treatment effects for this patient group can be improved by providing a combined treatment
program for SUD and PTSD (Donovan, Padin-Rivera, & Kowaliw, 2001; Driessen et al., 2008;
McGovern et al., 2009; Najavits et al., 2007; Rash, Coffey, Baschnagel, Drobes, & Saladin,
2008). However, to ascertain appropriate treatment allocation, the identification of PTSD during
pre-treatment assessment is crucial. Worryingly, despite the high prevalence of PTSD among
patients with SUD, earlier research has shown a low detection rate of PTSD within substance
abuse treatment centers (Kimerling et al., 2006; Reynolds et al., 2005). It appears to be that
patients do not often report traumatic experiences and PTSD symptoms on their own accord.
There is evidence that systematic screening can lead to a four-times-higher-detection of PTSD
among patients with SUD (Kimerling et al., 2006). Therefore, screening for PTSD during intake
for SUD treatment is of great clinical importance and seems to be a necessary first step to
improve treatment results for this patient group.
In addition to good diagnostic efficiency, screening instruments for PTSD should ideally
consist of few items only and have simple response scales and simple scoring methods (Brewin,
2005; National Collaborating Centre for Mental Health, 2005). The Primary Care posttraumatic
stress disorder screen (PC-PTSD) (Prins et al., 2003) has been developed as a short and simple
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screening questionnaire for PTSD (Davis & Whitworth, 2009). The list consists of four yes/ no
questions representing the PTSD symptom clusters reexperiencing, avoidance/ numbing and
increased arousal. The PC-PTSD was originally developed in a Veteran Affairs (VA) primary
care setting (Prins et al., 2003) and has been widely used in the U.S. army (e.g. Chan, Cheadle,
Reiber, Unutzer, & Chaney, 2009; Gore, Engel, Freed, Liu, & Armstrong, 2008; Hoge,
Auchterlonie, & Milliken, 2006; Milliken, Auchterlonie, & Hoge, 2007; Seal et al., 2008). To
date, its diagnostic qualities have exclusively been studied within VA settings, showing high
sensitivity and specificity values for cutoff scores 2 (sensitivity >.84; specificity >.70) and 3
(sensitivity >.75; specificity >.86) in this population (Bliese et al., 2008; Prins et al., 2003).
Initially, a cutoff of 2 was recommended for the PC-PTSD. In 2005, the VA increased the
thresh (Seal et al., 2008).
In a recent study, the diagnostic efficiency of the PC-PTSD for diagnosing PTSD was
investigated among VA patients with SUD (Kimerling et al., 2006). Results suggest that the
instrument is also suitable as a screener for an SUD population. Cutoff 3 showed high sensitivity
(.91) and specificity (.80) in this group. When applying cutoff 2, even higher sensitivity but lower
specificity were found (sensitivity = .97; specificity = .57)
A number of other questionnaires have been evaluated as screening measures for PTSD in
SUD populations, including the Impact of Event Scale (Weiss & Marmar, 1997; 15 items), PTSD
Checklist Civilian Version (Weathers, Litz, Huska, & Keane, 1994; 17 items), the Penn
Inventory (Hammarberg, 1992; 26 items), and the modified version of the PTSD Symptom Scale
- Self-Report (Falsetti, Resnick, Resick, & Kilpatrick; 17 items). However, the utility of these
measures for screening purposes appears questionable because all four questionnaires are rather
long (15-26 items).
Given its high diagnostic efficiency and the fact that the questionnaire is brief and easy to
use, the PC-PTSD is currently the most promising screening measure for PTSD in SUD samples.
Nevertheless, more research is needed before it can be recommended for use in routine clinical
care. The diagnostic efficiency of the measure in SUD samples has only been tested in one study
to date (Kimerling et al., 2006), whereas screening measures often show much poorer properties
in replication samples than in the original samples (Ehring, Kleim, Clark, Foa, & Ehlers, 2007).
In addition, particular caution is required when generalizing results from military to civilian
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populations. For example, earlier studies found a higher diagnostic cutoff point of the PTSD
Checklist (PCL) in veteran samples than in civilian samples (Forbes, Creamer, & Biddle, 2001;
Prins et al., 2003; Walker, Newman, Dobie, Ciechanowski, & Katon, 2002), and there are
indications that VA subjects report relatively more PTSD symptoms compared to civilians
(Bliese et al., 2008; Frueh, Hamner, Cahill, Gold, & Hamlin, 2000).
The first aim of the current study was to replicate and cross-validate the PC-PTSD in a
civilian sample of patients with SUD. Second, we aimed to test whether the capacity of the short
PC-PTSD to detect PTSD is as good as the longer Posttraumatic Diagnostic Scale (PDS) (Foa,
Cashman, Jaycox, & Perry, 1997), a widely used self-report questionnaire assessing all 17 PTSD
symptoms that has been shown to have high diagnostic efficiency for diagnosing PTSD (Ehring
et al., 2007). Final aim of this study was to evaluate an extended version of the PC-PTSD. Earlier
research has shown arousal and numbing to be linked to substance use in PTSD samples
(Najavits, 2003; Saladin, Brady, Dansky, & Kilpatrick, 1995; Shipherd, Stafford, & Tanner,
2005; Stewart, Conrod, Pihl, & Dongier, 1999). A possible explanation for this relationship is
that high levels of hyperarousal may motivate PTSD patients to abuse alcohol or drugs in an
attempt to self-medicate (Stewart & Conrod, 2003). Substance abuse in turn may maintain
emotional numbing in PTSD (Stewart, 1996). On the basis of this evidence, we aimed to test
whether an addition of arousal and numbing items to the PC-PTSD may increase the sensitivity
and/or specificity of the screener within a SUD population. Four extra items were added to the
original list, assessing increased physiological responding to trauma reminders (1 item),
hyperarousal (2 items) and numbing (1 item).
Method
Participants
Participants were (self-) referrals to the Jellinek, a large substance abuse treatment center
in Amsterdam, The Netherlands. Subjects participated in the study during the intake phase,
before entering formal treatment. Inclusion criteria were the following: (a) a diagnosis of
substance abuse or substance dependence according to the Diagnostic and Statistical Manual of
Mental Disorders, Fourth Edition (DSM-IV, American Psychiatric Association, 1994); (b) being
18 years or older, and (c) having sufficient fluency in Dutch to understand research procedures.
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Exclusion criteria were (a) nicotine dependency as the only SUD, (b) severe psychiatric problems
that required acute clinical care (e.g., psychotic symptoms, manic episode, and depression with
suicidal ideation), and (c) severe cognitive disorders. In addition, patients showing prominent
intoxication or withdrawal that obstructed routine intake procedures were not asked to fill out the
screener. After completing the screener patients were referred to the diagnostic interview by the
psychologist/social worker doing the intake.
Measures
Diagnostic interviews. SUD diagnoses were assessed during the intake. Additional DSM-
IV axis I disorders, including PTSD, were assessed with the Structured Clinical Interview for
DSM-IV axis I Disorders (First, Spitzer, Gibbon, & Williams, 1996). The SCID incorporates the
use of obligatory questions, operational criteria from the DSM-IV, a categorical system for rating
symptoms, and an algorithm for arriving at a final diagnosis.
Screening questionnaires. The Dutch version of the PC-PTSD (Prins et al., 2003) was
used to screen for PTSD. The questionnaire consists of four items with a yes/no response format,
whereby the symptom clusters reexperiencing (
that was so frightening, horrible, or upsetting that, in the past month, you: 1. Have had
nightmares about it or thought about it when you did not want to? ), avoidance 2. Tried hard
not to think about it or went out of your way to avoid situations that reminded you of it? ,
hyperarousal 3. Were constantly on guard, watchful, or easily startled? and numbing 4. Felt
) are represented by one item
each. The screener has been validated in a VA primary care population (Prins et al., 2003) and a
VA SUD population (Kimerling et al., 2006) and has shown good diagnostic efficiency in both
settings. In this study, four extra items were added to the PC-PTSD assessing physiological
Have experienced physical reactions, for example,
break out in a sweat, heart beats fast numbing (1 item 6. Felt that your future plans or hopes
will not come true as a consequence of the experience? ), and increased arousal (2 items 7. Had
trouble falling or staying asleep as a consequence of the experience? Had trouble
concentrating as a consequence of the experience? s of a pilot study (N = 49) among
civilian patients with SUD, which was run by the authors in preparation for this study, suggested
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that a substantial proportion of participants did not understand that the screener referred to
traumatic experiences instead of stressful life events (divorce, job loss, homelessness). Therefore,
it appeared necessary to modify the instruction for the PC-PTSD. The modified PC-PTSD used in
this study first provides participants with a list of potentially traumatizing events (e.g., serious
accident, rape, sexual abuse), and participants are instructed to mark the events they have
experienced in the past.
The PDS (Foa et al., 1997) was used as a second measure for PTSD. The questionnaire
consists of 17 items corresponding to the DSM-IV PTSD symptoms that are rated on a 4-point
Likert-scale (0 = not at all or only one time; 3 = five or more times a week/almost always). The
questionnaire furthermore consisted of nine yes/no items assessing impairment in different life areas.
Symptom severity scores are obtained by summing the 17 symptom items, with higher scores
indicating greater symptomatology. The PDS has shown good reliability and validity in the past (Foa
et al., 1997; Sheeran & Zimmerman, 2002), including high sensitivity and specificity (Ehring et al.,
2007). The PDS was included in this study to test whether the diagnostic efficiency of the short PC-
PTSD is comparable to that of a more comprehensive measure assessing all 17 PTSD symptoms.
Procedure
Patients meeting inclusion criteria received the extended version of the PC-PTSD and the
PDS during the intake. Regardless of their PC-PTSD score, all patients were invited to participate
in the SCID-I interview to establish diagnoses of PTSD and comorbid disorders. Before the
interview, written informed consent was obtained. To prevent bias, interviewers were kept blind
ostic information from the
patient file. Patients were blind for the exact purpose of the interview. They were told that the
interview aimed to assess psychological complaints in general for research purposes, without
specifically mentioning traumatic events or PTSD. The SCID-I interview was administered by
received intensive training on
how to conduct state-of-the-art SCID-I interviews. New assessors observed a large number of
SCID-I interviews and received one-to-one supervision by experienced assessors before they
were allowed to perform SCID-I assessments on their own. Furthermore, SCID-I assessments
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were monitored in weekly supervision sessions by a licensed supervisor. Discrepancies were
resolved during supervision meetings.
Data analyses
To establish the diagnostic properties of the screener, sensitivity (chance of screening
positive while having a true diagnosis), specificity (chance of screening negative while not
having a diagnosis), positive predictive power (PPP: chance of having a positive diagnosis after
screening positive), negative predictive power (NPP: chance of having a negative diagnosis after
screening negative) and overall efficiency (OE: chance of being classified appropriately) were
computed. Receiver operating characteristic (ROC) analyses were conducted considering
different cutoffs weighing sensitivity versus specificity. Results were compared against the
minimum quality standards suggested by Ehring et al. (2007), which were defined as a minimum
sensitivity and specificity of .75 and an OE of at least .80. Considering the purpose of the screener
in SUD treatment settings, a high sensitivity can be regarded as the most important quality
(Baldessarini, Finkelstein, & Arana, 1983) .
Results
Sample characteristics
A total of 147 participants were recruited to participate in the study. Five participants
were excluded because they reported psychotic symptoms (N = 4) or showed insufficient
knowledge of the Dutch language (N = 1). Four participants omitted one item of the (extended)
PC-PTSD (Item 3, N = 1; Item 6, N = 3), but were nevertheless included in the analyses
(excluding these participants did not change the results). The final sample therefore consisted of
142 participants. Most participants (89%) had used substances in the last month prior to the
diagnostic interview. According to the SCID-I, 14.8% of the sample (N = 21) met full DSM-IV
criteria for PTSD, and an additional 10.6% (N = 15) met criteria for partial PTSD (subthreshold
PTSD; defined as meeting symptom criteria for the reexperiencing cluster and for either the
avoidance/numbing cluster or the hyperarousal cluster) (Blanchard, Hickling, Taylor, Loos, &
Gerardi, 1994).
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Sample characteristics are displayed in Tables 1 and 2. The diagnostic groups did not
differ regarding age, F(2, 139) = 1.54, p = .22, type of substance use (all ² p
or ethnicity, relationship status, education and source of income (all ² p ).
However, a significant difference was found for gender, ² (2, N = 142) = 21.85, p < .001. The
percentage of women was higher in the PTSD and subthreshold PTSD groups than in the group
without clinically significant PTSD symptoms. Frequencies of reported traumatic experiences are
also presented in Table 2. Most participants with PTSD had experienced multiple traumas, with
physical violence/ assault and physical intimidation as the most frequent events.
Diagnostic efficiency of the original PC-PTSD
First, the diagnostic efficiency of the original PC-PTSD in identifying PTSD according to
the SCID was tested. The area under the curve (AUC) obtained from the ROC was .80 in
detecting a diagnosis of PTSD. In earlier research, a cutoff score of 3 has been recommended
(Kimerling et al., 2006; Prins et al, 2003). When applying this cutoff in this study, only moderate
values for sensitivity (.67) and specificity (.72) were found.
To check whether the diagnostic efficiency of the PC-PTSD can be improved by choosing
a different cutoff, analyses were repeated for a range of cutoffs (see Table 3). A cutoff score of 2
was found to be optimal, increasing the sensitivity to .86 while showing moderate specificity (.57).
Diagnostic efficiency of the extended PC-PTSD
Second, the diagnostic efficiency of the extended PC-PTSD comprising eight items was
tested (AUC = .79). Table 3 shows the sensitivities, specificities, PPP, NPP and OE for different
cutoffs applied to the extended PC-PTSD. The best results were found for a cutoff of 3. However,
the diagnostic efficiency did not exceed the one found for the original PC-PTSD with a cutoff of
2.
Next, we tested whether a new combination of items from the extended PC-PTSD would
improve the diagnostic efficiency. The sensitivities, specificities, PPP, and NPP were calculated
for each item separately (see Table 3). Four items (items 1, 2, 3, and 6) were found to show
sensitivities greater than .75 (and specificities >.61), and these items were combined to form a
new screening instrument. The diagnostic efficiency for this new measure at different cutoffs is
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shown in Table 3. The best results were found for a cutoff of 2, which resulted in slightly higher
sensitivity, specificity, and OE than the original PC-PTSD.
Diagnostic efficiency of the PDS
To test how well the PC-PTSD compares to the diagnostic efficiency of a self-report
measure including all 17 DSM-IV PTSD symptoms, the diagnostic efficiency of the PDS for
detecting PTSD according to the SCID-I was calculated considering cutoffs on the PDS total
severity scale (AUC = .81). Diagnostic efficiencies for cutoffs with sensitivities greater than .75
are displayed in Table 4. Optimal results were found for a cutoff of 14 (sensitivity, .86;
specificity, .61). This is equivalent to the diagnostic efficiency of the original PC-PTSD and
slightly inferior to the newly assorted scale, comprising Items 1, 2, 3 and 6 of the extended PC-
PTSD.
Diagnostic efficiency in detecting subthreshold PTSD
To test diagnostic efficiency of the different criteria in detecting subthreshold PTSD, all
analyses were repeated using a diagnosis of subthreshold PTSD according to the SCID-I instead
of full-blown PTSD as the criterion. Results are shown in Table 5. Optimal cutoff scores and
values for sensitivity and specificity (Table 5) were similar to those found for detecting a
conventional PTSD diagnosis (cutoff = 2 for the original PC-PTSD, cutoff = 3 for the extended
PC-PTSD). Again, the extended PC-PTSD did not exceed diagnostic efficiency compared to the
original PC-PTSD, and the new item combination of Items 1, 2, 3 and 6 showed a slight
improvement in diagnostic efficiency. In all analyses, PPP and OE values were substantially
higher for detecting subtreshold PTSD than for full-blown PTSD.
Diagnostic qualities of the PDS for detecting subthreshold PTSD were similar to the
original PC-PTSD, the extended PC-PTSD, and the new item combination (Items 1, 2, 3 and 6).
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Table 1. Sample Characteristics: Demographics.
Demographics
Total sample
(N = 142)
SUD/ PTSD
(N = 21)
SUD/ Partial PTSD
(N = 15)
SUD/ No PTSD
(N = 106)
Mean age (SD) 43.3 (10.21) 44.1 (9.10) 38.9 (7.7) 43.7 (10.6)
Gender, n (%)
Male 105 (73.9) 9 (42.9) 7(46.7) 89 (84.0)
Female 37 (26.1) 12 (57.1) 8 (53.3) 17 (16)
Ethnicity, n (%)
Caucasian/ Dutch 93 (65.5) 11 (52.4) 9 (60) 73 (68.9)
Caucasian/ European (other) 9 (6.3) 0 (0) 2 (13.3) 7 (6.6)
Arabic/ Moroccan/ Turkish 8 (5.6) 1 (4.8) 0 (0) 7 (6.6)
Black/ Surinamese/ Caribbean 13 (9.2) 3 (14.3) 1 (6.7) 9 (8.5)
Black/ African (other) 4 (2.8) 2 (9.5) 1 (6.7) 1 (0.9)
Other 5 (3.5) 2 (9.5) 0 (0) 3 (2.8)
Missing 10 (7.0) 2 (9.5) 6 (5.7)
Education (certificate), n (%)
No education, primary school 19 (13.4) 3 (14.3) 3 (20.0) 13 (12.2)
Secondary school, lower level* 35 (24.6) 4 (19) 4 (26.7) 27 (25.5)
Secondary school, higher level * 37 (26.1) 8 (38.1) 4 (26.7)) 25 (23.6)
Postsecondary* 36 (25.4) 2 (9.5) 2 (13.3) 32 (30.2)
Missing 15 (10.6) 4 (19) 2 (13.3) 9 (8.4)
Relationship status, n (%)
Single 78 (54.9) 11 (52.4) 11 (73.3) 56 (52.8)
Married/ living with partner 25 (17.6) 1 (4.8) 1 (6.7) 24 (22.7)
Separated/ divorced 21 (14.8) 5 (23.8) 0 (0) 15 (14.2)
Missing 18 (12.7) 4 (19) 3 (20.0) 11 (10.3)
Source of income, n (%)
None 10 (7) 2 (9.5) 0 (0) 8 (7.5)
Benefits 51 (35.9) 5 (23.8) 6 (40.0) 38 (35.9)
Work 65 (45.8) 10 (47.6) 5 (33.3) 50 (47.2)
Other 4 (2.8) 1 (4.8) 2 (13.3) 3 (2.8)
Missing 12 (8.5) 3 (14.3) 2 (13.3) 7 (6.6)
Note. SUD = Substance use disorder. PTSD = Posttraumatic stress disorder. * Level of education: secondary school, lower level = VBO/LBO/MAVO/Avo; secondary school, higher level = HAVO, VWO, MBO; postsecondary = HBO, university, doctor of philosophy.
2
(13
.
3)
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Table 2. Sample Characteristics: Substance Use Disorders and Traumatic Events.
Characteristics
Total sample
(N = 142)
SUD/ PTSD
(N = 21)
SUD/ Partial PTSD
(N = 15)
SUD/ No PTSD
(N = 106)
Substance use disorders, n (%)
Alcohol dependence 89 (62.7) 12 (57.1) 8 (53.3) 69 (65.1)
Alcohol abuse 31 (21.8) 6 (28.6) 3 (20.0) 22 (79.2)
Cannabis dependence 52 (37.0) 8 (38.1) 8 (53.3) 36 (34.0)
Cannabis abuse 2 (1.0) 0 (0) 0 (0) 2 (1.9)
Cocaine dependence 21 (14.7) 4 (19.0) 3 (20.0) 14 (13.2)
Cocaine abuse 12 (8.5) 2 (9.5) 2 (13.3) 8 (7.5)
Sedative dependence 10 (7.0) 1 (4.8) 3 (20.0) 6 (5.7)
Sedative abuse 7 (4.9) 0 (0) 1 (6.7) 6 (5.7)
Opiate dependence 0 (0) 0 (0) 0 (0) 0 (0)
Opiate abuse 1 (0.7) 0 (0) 0 (0) 1 (0.9)
Amphetamine dependence 3 (2.1) 1 (4.8) 0 (0) 2 (1.9)
Amphetamine abuse 0 (0) 0 (0) 0 (0) 0 (0)
Traumatic events, n (%)
Any trauma reported 104 (73.2) 21 (100) 15 (100) 68 (64.2)
Single trauma 36 (25.4) 4 (19.0) 2 (13.3) 30 (28.3)
Multiple trauma 68 (47.9) 17 (81.0) 13 (86.7) 38 (35.8)
Physical intimidation 44 (31) 13 (61.9) 7 (46.7) 24 (22.6)
Serious accident 26 (18.3) 4 (19) 5 (33.3) 17 (16.0)
Disaster 3 (2.1) 1 (4.8) 0 (0) 2 (1.9)
Physical violence/assault 61 (43.0) 18 (85.7) 11 (73.3) 32 (30.2)
Rape/ sexual violence/ sexual abuse 34 (23.9) 12 (57.1) 10 (66.7) 12 (11.3)
War 6 (4.2) 3 (14.3) 1 (6.7) 2 (1.9)
Other traumatic events 43 (30.3) 6 (28.6) 3 (20.0) 34 (32.1)
Note. SUD = Substance use disorder. PTSD = Posttraumatic stress disorder.
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Table 3. Diagnostic Efficiency of the PC-PTSD Detecting a Diagnosis of PTSD.
Criterion Cutoff Sensitivity Specificity PPP NPP OE
PC-PTSD 2 .86 .57 .26 .96 .61
3 .67 .72 .29 .93 .71
4 .52 .88 .42 .91 .82
Extended PC-PTSD (8 items) 3 .86 .56 .25 .96 .61
4 .76 .60 .25 .94 .63
5 .62 .68 .25 .91 .67
6 .62 .73 .28 .92 .71
7 .62 .79 .34 .92 .77
Individual items
Item 1 - .81 .67 .30 .95 .69
Item 2 - .76 .71 .31 .94 .72
Item 3 - .76 .61 .25 .94 .63
Item 4 - .71 .58 .23 .92 .60
Item 5 - .71 .64 .26 .93 .65
Item 6 - .80 .61 .26 .95 .64
Item 7 - .71 .61 .24 .92 .62
Item 8 - .67 .64 .24 .92 .64
Combination of items 1, 2, 3, 6 2 .91 .62 .29 .97 .66
3 .67 .70 .28 .92 .70
4 .52 .84 .37 .92 .80
Note. PC-PTSD = Primary Care posttraumatic stress disorder screen. PTSD = Posttraumatic stress disorder. PPP = Positive predictive power. NPP = Negative predictive power. OE = Overall efficiency. The table presents results for all cutoffs resulting in sensitivity and specificity values exceeding .50 (i.e., greater than chance) in detecting positive or negative cases.
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Table 4. Diagnostic Efficiency of the PDS Detecting a Diagnosis of PTSD.
Criterion Cutoff Sensitivity Specificity PPP NPP OE
PDS 12 .86 .57 .26 .96 .61
13 .86 .59 .27 .96 .62
14 .86 .61 .28 .96 .65
15 .81 .61 .27 .95 .65
18 .77 .67 .29 .94 .68
19 .76 .68 .30 .94 .70
20 .76 .71 .31 .94 .72
Note. PDS = Posttraumatic Diagnostic Scale. PTSD = Posttraumatic stress disorder. PPP = Positive predictive power. NPP = Negative predictive power. OE = Overall efficiency.
Table 5. Diagnostic Efficiency of Different Criteria for Detecting Partial PTSD.
Criterion Cutoff Sensitivity Specificity PPP NPP OE
PC-PTSD 2 .86 .63 .44 .93 .69
3 .67 .77 .50 .87 .75
4 .50 .92 .69 .84 .82
Extended PC-PTSD (8 items) 3 .86 .62 .44 .93 .68
4 .81 .67 .45 .91 .70
5 .67 .74 .46 .87 .72
6 .67 .79 .52 .88 .76
7 .58 .84 .55 .86 .77
8 .67 .93 .39 .82 .80
Combination of items 1, 2, 3, 6 1 .97 .50 .40 .98 .62
2 .89 .69 .49 .95 .74
3 .67 .75 .48 .87 .73
4 .53 .90 .63 .85 .80
PDS 12 .83 .62 .43 .92 .73
13 .83 .65 .45 .92 .70
14 .81 .66 .45 .91 .70
15 .75 .66 .43 .89 .68
Note. PC-PTSD = Primary Care PTSD screen. PTSD = Posttraumatic stress disorder. PPP = Postive predictive power. NPP = Negative predictive power. OE = Overall efficiency.
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Discussion
The first aim of this study was to cross-validate the PC-PTSD as a brief PTSD screening
instrument in civilian SUD patients. When applying the current VA cutoff score norm of 3, only
moderate values for sensitivity (.67) and specificity (.72) were found, which are considerably
lower than those obtained in earlier research amongst VA patients with SUD (Kimerling et al.,
2006). Sensitivity could be increased to .86 using a cutoff score of 2 (specificity = .57). In other
words, out of 100 patients with PTSD, 86 will be detected by the screener, and of 100 patients
without a diagnosis for PTSD, 57 will be correctly identified as having no PTSD. There are no
universal criteria to decide what constitutes a good performance of a screening instrument as the
relative importance of sensitivity and specificity depends on the nature of the diagnostic situation
(Baldessarini, Finkelstein, & Arana, 1983). However, it can be argued that to identify PTSD
among patients with SUD, high sensitivity has a priority above other diagnostic qualities. The PC-
PTSD with a cutoff of 2 appears to be most suitable for this purpose.
Using a cutoff of 2 is in line with the advice given by Prins et al. (2003) to choose a cutoff
of 2 if sensitivity rather than OE should be optimized. However, it should be noted that our
results differ from findings of Kimerling et al. (2006). This discrepancy may reflect a systematic
difference between military and civilian samples, though. For example, there is evidence for
higher cutoffs on the PCL for military personnel when compared to civilians (Forbes et al., 2001;
Prins et al., 2003; Walker et al., 2002). There are also indications that VA subjects report
relatively more PTSD symptoms compared to civilian PTSD patients (Bliese et al., 2008; Frueh
et al., 2000). In their review, Frueh et al. (2000) describe several hypotheses to explain this
phenomenon (severity of actual illness, single global distress factor, compensation-seeking status,
malingering, and sociopolitical considerations). Another explanation might be data collection
procedures used in a number of VA samples (e.g. surveillance research instead of clinical
research) (Bliese et al., 2008).
Although speculative, an explanation for a lower optimal cutoff for the PC-PTSD in our
study might be the possible overreporting on Item 3 in military samples compared to civilians.
This item is sc constantly on guard, watchful, or easily startled .
For some sol might symbolize necessary
professional characteristics rather than a pathological symptom.
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The second aim of this study was to test diagnostic efficiency of the PC-PTSD for the
assessment of PTSD compared to a number of other instruments. The performance of the PC-
PTSD was found to be equal to the PDS, a self-report questionnaire of PTSD symptom severity
assessing all 17 DSM-IV criteria (Foa et al., 1997). The diagnostic efficiency did not improve by
adding additional items to build an extended eight-item version of the PC-PTSD. Finally, a new
four-item measure assembled in this study by combining the most sensitive items of the extended
PC-PTSD was tested. This resulted in slightly higher sensitivity (.91 vs. .86) and specificity
values (.62 vs. .57). However, because this new item combination was established post-hoc,
these values are likely to be inflated; therefore, these findings need to be cross-validated in an
independent sample before any strong conclusions regarding a superiority over the PC-PTSD can
be drawn (Ehring et al., 2007). Interestingly, results for the PC-PTSD and its comparison with
other screening instruments were similar for full-blown PTSD and subthreshold PTSD.
Therefore, the screener appears to be suitable for the detection of both disorders.
Although the results of this study support diagnostic efficiency of the PC-PTSD in a civilian
SUD population, our study has several limitations. The fact that the screening questionnaire was
given while patients were still using substances is a strength of this study, as it mirrors the
situation during intake in clinical practice. However, the SCID-I was also conducted while most
patients had used substances in the weeks prior to the interview. Although patients showing
prominent intoxication were not included, there is a chance that PTSD symptoms reported during
the diagnostic interview were influenced by recent substance use. A recommendation for future
research would be to repeat the SCID-I interview after 4 weeks of abstinence. Another limitation
concerns the generalizability of the results. First of all, the base rate of PTSD is relatively low in
our sample. Although trauma rate in our sample was comparable to findings in other studies, only
14.8% of our subjects met full criteria for PTSD and an additional 10.6% met partial criteria. The
incidence of PTSD in our sample is therefore somewhat lower than found in earlier studies
among SUD populations (e.g. Harrington & Newman, 2007; Hyman, Garcia, Kemp, Mazure, &
Sinha, 2005; Ouimette et al., 2006). A number of possible explanations for this discrepancy are
conceivable. First, it may be due to procedural differences. In our study, interviewers were
-PTSD and PDS scores to prevent response bias. In addition, to
prevent overreporting of trauma or PTSD symptoms, patients were told that the interview was
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36
about psychological complaints in general, without specifically mentioning trauma or PTSD. To
our knowledge, these procedures were not used in earlier studies, which might have led to more
participants reporting PTSD symptoms in earlier studies as they were primed regarding the
purpose of the interview.
Second, the lower rate of PTSD in our sample may partly be due to the fact that
educational level was rather high. Earlier research has shown intelligence to be negatively related
to PTSD (Breslau, Lucia, & Alvarado, 2006; McNally & Shin, 1995). In addition, our sample
consisted of significantly more men than women, whereas women apparently have a higher
vulnerability for PTSD (Olff, Langeland, Draijer, & Gersons, 2007). Finally, differences in
cultural aspects and/or characteristics of the health care systems in the Netherlands versus the
United States may have contributed to the relatively lower prevalence of PTSD in our sample.
There is some indication that the conditional risk of developing PTSD in trauma survivors may
be somewhat lower in the Dutch populations (Bronner et al., 2009) when compared to the U.S.
populations (Kessler, Sonnega, Bromet, Hughes, & Nelson, 1995 ). In addition, PTSD treatments
are readily available for individuals living in the Netherlands and paid for by national health care
insurance. This may lead to a relatively early detection and treatment of PTSD before secondary
substance abuse is developed.
The generalizability of the present findings is furthermore limited by the fact that we
investigated a specific group of patients with SUD. At the Jellinek substance abuse treatment
center, a distinction is made between abstinence/controlled use-orientated treatment programs
(e.g. motivational interviewing, cognitive behavioral treatment) and harm-reduction programs
(continuous medical and/or psychosocial support). This study was conducted in patients being
assessed for abstinence/controlled use-orientated treatment programs only. Future research is
needed to test whether the results can be replicated in the more severe group of chronic care
patients.
A further limitation may be the fact that PTSD was assessed using the SCID-I but not the
Clinician-Administered PTSD Scale (CAPS) (Blake et al., 1990), which is often regarded as the
gold standard. Reassuringly, earlier research has found a high agreement between PTSD
diagnoses established with the SCID-I and the CAPS (Foa, & Tolin, 2000). Future studies should
also establish interrater reliability, which was not available in this study.
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Finally, the instruction for the PC-PTSD was slightly adapted for this study. Participants
were first provided with a list of traumatic events and asked to indicate whether they had
experienced any of these events. This modification appeared necessary based on findings of a
pilot study conducted in the same population, which showed that a relatively large number of
participants did not understand the meaning of traumatic experiences. It is unclear whether this
adaptation has influenced the results in any major way. Future research is needed to directly test
the diagnostic efficiency of the original PC-PTSD and its modified version used in this study.
Despite these limitations, results of this study suggest that the PC-PTSD can be a useful
screening instrument for PTSD in a civilian SUD population. In our study, the PC-PTSD showed
a good sensitivity, which can be regarded as the most important property when screening for
PTSD in a substance abuse treatment center. In addition, it performed equally to the 17-item PDS
and an extended version of the PC-PTSD. However, the PC-PTSD showed only moderate
specificity. It can therefore be expected to lead to a number of false positives when used in
clinical practice. Future research is needed to test whether the specificity of the measure can be
improved or whether the suboptimal specificity is simply due to the complex symptom
presentation in nonabstinent populations. This finding has important clinical implications because
screening for PTSD among SUD patients during pre-treatment assessment is crucial to ascertain
appropriate treatment allocation for patients with SUD suffering from PTSD symptoms.
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CChapter 3
Screening for posttraumatic stress disorder in civilian
substance use disorder patients: cross-validation of the
Jellinek-PTSD screening questionnaire
Van Dam, D., Ehring, T., Vedel, E., & Emmelkamp, P. M. G. (2013). Screening for posttraumatic stress disorder in
civilian substance use disorder patients: Cross-validation of the Jellinek-PTSD screening questionnaire. Journal of
substance abuse treatment, 44, 126-131.
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Abstract This study aimed to cross-validate earlier findings regarding the diagnostic efficiency of a
modified version of the Primary Care posttraumatic stress disorder screen (PC-PTSD). The PC-
PTSD is a 4-item screening questionnaire for posttraumatic stress disorder (PTSD). Based on
former research, we adapted the PC-PTSD for use among civilian substance use disorder (SUD)
patients. This version will be referred to as the Jellinek-PTSD screening questionnaire (J-PTSD).
Results showed a high sensitivity (.87), specificity (.75), and overall efficiency (.77) of the J-
PTSD in detecting PTSD when using a cutoff score of 2. This confirms findings in former
research, and suggests that the J-PTSD is a useful screening instrument for PTSD within a
civilian SUD population. Both PTSD and SUD are severe and disabling disorders causing great
psychological distress. An early recognition of PTSD among SUD patients makes it possible to
address PTSD symptoms in time, which may ultimately lead to an improvement of symptoms in
this complex patient group.
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Introduction
The prevalence of posttraumatic stress disorder (PTSD) is high among patients with
substance use disorders (SUDs). Research has shown that approximately one of every three SUD
patients has a formal diagnosis for PTSD (Harrington & Newman, 2007; Kimerling, Trafton, &
Nguyen, 2006). Within this group, women are more likely to have a PTSD diagnosis than men
(Ouimette, Goodwin, & Brown, 2006). Patients with concurrent PTSD and SUD suffer from
more severe complaints and show worse treatment outcomes compared to patients with either
disorder alone (Back et al., 2000; Brown & Wolfe, 1994; Najavits, Weiss, & Shaw, 1999;
Ouimette, Brown, & Najavits, 1998). The sequential treatment of both disorders might contribute
to the poor prognosis of this patient group. Usually, patients have to complete SUD treatment
successfully before PTSD complaints are addressed (Van Dam, Vedel, Ehring, & Emmelkamp,
2012). However, both retrospective and experimental research suggests a functional relationship
between PTSD and SUD (Back, 2010; Back, Brady, Jaanimagi, & Jackson, 2006; Coffey et al.,
2002; Michael, 2003; Saladin et al., 2003; Stewart & Conrod, 2003). This implies that if one of
the disorders is treated separately, the other disorder is likely to exacerbate. A number of authors
have therefore suggested that an integrated treatment approach might be more appropriate
(McGovern et al., 2009; Najavits, 2007).
However, researchers and clinicians who want to implement integrated treatments are
faced with the practical problem of how to identify patients with concurrent PTSD and SUD.
Earlier research has shown that regardless of their high prevalence, PTSD complaints often stay
unnoticed within substance abuse treatment centers (Kimerling et al., 2006; Reynolds et al.,
2005). Reassuringly, systematic screening for PTSD among SUD patients has shown to improve
the detection rate substantially (Kimerling et al., 2006). Screening instruments with established
high diagnostic properties are needed to implement such an approach in routine clinical settings.
A number of requirements for screening instruments for PTSD have been suggested in the
literature. Most importantly, the measures should have good diagnostic qualities to identify
PTSD, and should be easily administered and interpreted (Brewin, 2005; National Collaborating
Centre for Mental Health, 2005). These aspects are especially important when screening for
PTSD among SUD patients, because during intake most patients are still using substances that
may influence comprehension and concentration. The Primary Care posttraumatic stress disorder
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screen (PC-PTSD) (Prins et al., 2003) is a short and simple screening questionnaire for PTSD
(Davis & Whitworth, 2009) that has been shown to meet these requirements. The questionnaire
consists of four yes/no questions representing the PTSD symptom clusters reexperiencing,
avoidance/ numbing, and increased arousal. The PC-PTSD has successfully been used in
substance use populations (Deady, 2009; Ford, Hawke, Alessi, Ledgerwood, & Petry, 2007;
Goldstein, Asarnow, Jaycox, Shoptaw, & Murray, 2007). However, until recently its diagnostic
qualities were exclusively investigated among veterans treated at VA primary care (Bliese et al.,
2008; Prins et al., 2003) or SUD departments (Kimerling et al., 2006).
In a recent study, a modified version of the PC-PTSD was evaluated in a group of civilian
SUD patients (Van Dam, Ehring, Vedel, & Emmelkamp, 2010). The instruction for the PC-PTSD
was adapted in that participants were first provided with a list of traumatic events and asked to
indicate whether they had experienced any of these events. This modification appeared necessary
based on findings of a pilot study conducted in the same population, which showed that a lot of
Van Dam et al.
(2010) found a sensitivity of .86, and a specificity of .57 for the PC-PTSD (cutoff score = 2). The
performance of the PC-PTSD was found to be equal to the Posttraumatic Diagnostic Scale (Foa,
Cashman, Jaycox, & Perry, 1997), a self-report questionnaire of PTSD symptom severity
assessing all 17 criteria of the fourth revision of the Diagnostic and Statistical Manual (DSM-IV;
American Psychiatric Association [APA], 1994). In addition, the diagnostic efficiency did not
improve by adding four additional items to the PC-PTSD referring to arousal and numbing
symptoms, which are assumed to be linked to substance use in PTSD samples (Najavits et al.,
2003; Saladin, Brady, Dansky, & Kilpatrick, 1995; Shipherd, Stafford, & Tanner, 2005; Stewart,
Conrod, Pihl, & Dongier, 1999). However, accumulating the four most sensitive items (>.75)
resulted in slightly higher sensitivity (.91), and specificity values (.62). In the current article, this
new item combination will be referred to as the Jellinek-PTSD screening questionnaire (J-PTSD).
In sum, the J-PTSD is based on the PC-PTSD but (1) includes an adapted instruction providing
participants with a list of traumatic events and asking them to indicate whether they have
experienced any of these events, and (2) combines the first three items from the original PC-
PTSD with a new item enquiring about the feeling that future plans or hopes will not come true
as a consequence of the experience.
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In the earlier study by Van Dam et al. (2010), the J-PTSD showed good diagnostic
properties. However, as the best item combination and cutoff were established post-hoc, cross-
validation is necessary before any strong conclusions can be drawn regarding its diagnostic
efficacy in detecting PTSD among civilian SUD patients (see Ehring, Kleim, Clark, Foa, &
Ehlers, 2007; Van Dam et al., 2010). The aim of the current study was to cross-validate the J-
PTSD in an independent sample of SUD patients.
Method
Participants
Participants were consecutive (self-)referrals to a large substance abuse treatment center,
the Jellinek, in Amsterdam, The Netherlands. Subjects participated in the study during the intake,
before entering formal treatment. Inclusion criteria were: (1) a diagnosis of substance abuse or
substance dependence according to DSM-IV, (2) being 18 years or older, and (3) having sufficient
fluency in Dutch to understand research procedures. Exclusion criteria were (1) nicotine
dependency as the only SUD, (2) severe psychiatric problems that required immediate clinical
care (e.g., psychotic symptoms, manic episode and depression with suicidal ideation) and (3)
severe cognitive disorders. In addition, patients showing prominent intoxication or withdrawal
that obstructed routine intake-procedures were not asked to fill out the screener.
Measures
Diagnostic interviews. The Composite International Diagnostic Interview (CIDI vs 2.1.)
(World Health Organization, 1997) was carried out during the intake to obtain DSM-IV SUD
diagnoses. PTSD was diagnosed with the Structured Clinical Interview for DSM-IV axis I
Disorders (First, Spitzer, Gibbon, & Williams, 1996). The items of the SCID reflect the
diagnostic criteria of the DSM-IV.
Screening questionnaires. The J-PTSD, a Dutch modified version of the PC-PTSD
(Prins et al., 2003) was used to screen for PTSD (see Van Dam et al., 2010, for a description of
the development of the measure). The screener first provides a definition of traumatic events with
a list of potentially traumatic experiences (e.g., serious accident, rape, sexual abuse), including a
free category for other kinds of traumatic events. Participants were asked to mark all traumatic
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events they had experienced in the past. Participants who have never experienced any traumatic
event were instructed to stop filling out the questionnaire at that point. All other participants were
asked to fill out four yes/no items, reflecting respectively on reexperiencing, avoidance,
hyperarousal and numbing symptoms (see Appendix A). The first three items of the J-PTSD are
the same as in the original PC-PTSD. The fourth item of the original PC-PTSD referring to the
t numb or detached from others, activities, or
has been replaced by another item referring to the avoidance/ numbing
Procedure
From February 28, 2011 until March 28, 2011 data were collected from all patients
successively attending the Jellinek for an intake. During the intake interview, patients meeting
inclusion criteria were informed about the study, and written informed consent was obtained.
First, substance use was assessed using the CIDI and additional measures not reported in this
study. Then, patients were asked to fill out the J-PTSD without showing their responses to the
interviewer in order to keep him/her blind for screener results. After that, the interviewer
administered the PTSD-section of the SCID-I interview. All interviewers were psychologists and
had received specific training and supervision in conducting the CIDI and the PTSD-section of
SCID-I. In principle, the original questions of the SCID-I PTSD module were used. However,
interviewers were trained to provide extra examples for traumatic experiences (e.g., physical
violence and sexual abuse during childhood) to illustrate the type of events the questions refer to.
Data Analyses
In order to investigate the diagnostic qualities of the screener, sensitivity (chance of
screening positive while having a true diagnosis), specificity (chance of screening negative while
not having a diagnosis), predictive power (PPP: chance of having a positive diagnosis after
screening positive), negative predictive power (NPP: chance of having a negative diagnosis after
screening negative) and overall efficiency (OE: chance of being classified appropriately) were
computed. A receiver operating characteristic (ROC) analysis was carried out to evaluate
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50
different cutoffs weighing sensitivity versus specificity. Results were compared with earlier
findings for the J-PTSD (Van Dam, Ehring, Vedel, & Emmelkamp, 2010).
Results
Sample characteristics
Characteristics of the total sample (excluded and included participants). A total of
153 participants were interviewed for an intake during the period in which the study took place.
Sixty-one (39.9%) individuals were excluded from the study for the following reasons; 42.7%
had no SUD (e.g., patient presented with a single diagnosis for pathological gambling), or a
single diagnosis for nicotine dependency, 16.4% did not want to participate, 19.7% had severe
psychiatric or cognitive problems, or was prominently intoxicated, 11.5% had no sufficient
understanding of Dutch, and 9.8% reported other reasons not to participate. Ninety-two (60.1%)
individuals were included. No differences were found between the included and excluded group
regarding age F(1, 152) = 2.5, p = .12, p2 = 0.02, as well as gender, nationality, work status and
level of education (all p
Characteristics of the final sample (included participants only). The final sample
consisted of 92 participants. According to the SCID-I, 16.3% of the sample (N = 15) met full
DSM-IV criteria for PTSD, and 5.4% of the sample (N = 5) met criteria for partial PTSD, defined
as meeting symptom criteria for the reexperiencing cluster and for either the avoidance/numbing
cluster or the hyperarousal cluster (Blanchard, Hickling, Taylor, Loos, & Gerardi, 1994). Sample
characteristics are displayed in Table 1.
The sample comprised 70 men (76.1%), and 22 women (23.9%). The level of education
was relatively high since 43.5% of the patients had completed a higher level of secondary school.
Frequencies of substances used are presented in Table 2. Alcohol was the most frequently used
substance. Table 2 also presents an overview of the type of traumatic events participants had
experienced. The vast majority of patients with a diagnosis for PTSD reported multiple traumas.
Physical violence/assault and physical intimidation were most frequently reported (respectively
73.3% and 60%).
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Table 1. Sample characteristics: Demographics.
Demographics
Included
(N = 92)
SUD/ PTSD
(N =15)
SUD/ Part PTSD
(N = 5)
SUD/ No PTSD
(N = 72 )
Excluded
(N = 61)
Mean age (SD) 42.1 (11) 41 (11.8) 40 (11.9) 42.5 (10.9) 45.2 (12.5)
Gender, n (%)
Male 70 (76.1) 11 (73.3) 3 (60) 56 (77.8) 38 (62.3)
Female 22 (23.9) 4 (26.7) 2 (40) 16 (22.2) 23 (37.7)
Nationality, n (%)
Dutch 72 (78.3) 10 (66.7) 3 (60) 59 (81.9) 41 (67.2)
European (other) 5 (5.4) 2 (13.3) 1 (20) 2 (2.8) 5 (8.2)
Moroccan/Turkish 6 (6.5) 2 (13.3) 0 (0) 4 (5.6) 5 (8.2)
Surinamese/Caribbean 2 (2.2) 0 (0) 1 (20) 1 (1.4) 2 (3.3)
Other 2 (2.2) 0 (0) 0 (0) 2 (2.8) 5 (8.2)
Missing 5 (5.4) 1 (6.7) 0 (0) 4 (5.6) 3 (4.9)
Education (certificate), n (%)
No education, primary school 6 (6.5) 3 (20) 0 (0) 3 (4.2) 5 (8.2)
Secondary school, lower level 20 (21.7) 3 (20) 2 (40) 15 (20.8) 13 (21.3)
Secondary school, higher level 40 (43.5) 8 (53.3) 3 (60) 29 (40.3) 18 (29.5)
Postsecondary 21 (22.8) 1 (6.7) 0 (0) 20 (27.8) 14 (23)
Missing 5 (5.4) 0 (0) 0 (0) 5 (6.9) 11 (18.0)
Relationship status, n (%)
Single 9 (9.8) 1 (6.7) 0 (0) 8 (11.1) 1 (1.6)
Partner 83 (90.2) 14 (93.3) 5 (100) 64 (88.9) 9 (14.8)
Missing 0 (0) 0 (0) 0 (0) 0 (0) 51 (83.6)
Source of income, n (%)
No work 54 (58.7) 7 (46.7) 4 (80) 43 (59.7) 41 (67.2)
Work 37 (40.2) 8 (53.3) 1 (20) 28 (38.9) 17 (27.9)
Missing 1 (1.1) 0 (0) 0 (0) 1 (1.4) 3 (4.9)
Note. SUD = Substance use disorder. PTSD = Posttraumatic stress disorder. Part PTSD = Partial PTSD.
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Table 2. Sample Characteristics: Substance Use and Traumatic Events.
Characteristics
Total sample
(N = 92)
SUD/ PTSD
(n = 15)
SUD/ Partial PTSD
(n = 5)
SUD/ No PTSD
(n = 72)
Substances Used, n (%)
Alcohol 74 (80.4) 12 (80) 5 (100) 57 (79.2)
Cannabis 37 (40.2) 5 (33.3) 0 (0) 32 (44.4)
Cocaine 21 (22.8) 3 (20) 2 (40) 11 (15.3)
Opiates 2 (2.2) 0 (0) 0 (0) 3 (4.2)
Sedatives 5 (5.4) 1 (6.7) 0 (0) 4 (5.6)
Amphetamine 2 (2.2) 0 (0) 0 (0) 2 (2.8)
Other 1 (1.1) 0 (0) 0 (0) 0 (0)
Traumatic events, n (%)
Any trauma reported 53 (57.6) 15 (100) 5 (100) 33 (45.8)
Single trauma 24 (26.1) 1 (6.7) 1 (20) 22 (30.6)
Multiple trauma 28 (30.4) 14 (93.3) 4 (80) 10 (13.9)
Physical intimidation 19 (20.7) 9 (60) 1 (20) 9 (12.5)
Serious accident 18 (19.6) 4 (26.7) 2 (40) 12 (16.7)
Disaster 3 (3.3) 1 (6.7) 0 (0) 2 (2.8)
Physical violence/assault 28 (30.4) 11 (73.3) 4 (80) 13 (18.1)
Rape/ sexual violence/ sexual abuse 17 (18.5) 5 (33.3) 3 (60) 9 (12.5)
War 3 (3.3) 2 (13.3) 0 (0) 1 (1.4)
Other traumatic events 15 (16.3) 5 (33.3) 1 (20) 9 (12.5)
Note. SUD = Substance use disorder. PTSD = Posttraumatic stress disorder.
Table 3. Diagnostic Efficiency of the J-PTSD Detecting a Diagnosis of (partial) PTSD.
Diagnosis Cutoff Sensitivity Specificity PPP NPP OE
PTSD 1 .87 .64 .32 .96 .67 2 .87 .75 .41 .97 .77 3 .73 .84 .48 .94 .83 4 .60 .92 .60 .92 .87 Partial PTSD 1 .90 .68 .44 .96 .73 2 .85 .79 .53 .95 .80 3 .70 .88 .61 .91 .84 4 .55 .94 .73 .88 .86 Note. J-PTSD = Jellinek-PTSD screening questionnaire. PTSD = Posttraumatic stress disorder. PPP = Positive predictive power. NPP = Negative predictive power. OE = Overall efficiency.
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Diagnostic Efficiency of the J-PTSD
In a first step, ROCs were performed to investigate the diagnostic efficiency of the J-
PTSD identifying PTSD and partial PTSD. The areas under the curve (AUC) were respectively
.84 for PTSD and .87 for partial PTSD.
In a second step, diagnostic efficiency was calculated for the J-PTSD, using the cut off of
2 established in earlier research (Van Dam et al., 2010). High sensitivity, specificity and OE were
found in detecting both PTSD and partial PTSD (PTSD: sensitivity = .87, specificity = .75, OE =
.77; partial PTSD: sensitivity = .85; specificity = .79; OE = .80).
In a third step, it was tested whether the diagnostic efficiency of the J-PTSD could be
improved by choosing a different cutoff. Results showed that this was not the case. As expected, a
cutoff score of 2 gave optimal results in identifying both PTSD and partial PTSD (see Table 3).
Discussion
The aim of the current study was to replicate and cross-validate earlier findings for the J-
PTSD in a sample of civilian SUD patients. In a recent study, high sensitivity (.92), moderate
specificity (.62), and moderate OE (.66) were found using a cutoff score of 2 (Van Dam, Ehring,
Vedel, & Emmelkamp, 2010). Results of the current study confirmed the validity of this optimal
cutoff for the J-PTSD, in that high values were found for sensitivity (.87), specificity (.75), and
OE (.77) in detecting PTSD. This means that out of 100 patients with PTSD, 87 will be correctly
identified by the screener as having PTSD. Out of 100 patients without a diagnosis for PTSD, 75
will be correctly identified as having no PTSD. Additional analyses confirmed that a cutoff = 2
was indeed optimal. The high values found for sensitivity, specificity, and OE suggest that the
screener possesses good diagnostic qualities. Although the sensitivity is slightly lower than in the
former study, the specificity and the OE are substantially better. This indicates that the J-PTSD
can contribute to the efficiency in clinical practice. Using the J-PTSD, a large majority of patients
with PTSD will be correctly identified to be invited for in-depth assessment, while few patients
are invited unnecessarily.
The results for detecting partial PTSD with the J-PTSD were comparable to the findings
for full-blown PTSD. For partial PTSD, a sensitivity of .85, a specificity of .79 and an OE of .80
were found.
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In sum, the cross-validation of the J-PTSD was successful as good diagnostic qualities in
identifying PTSD were found. Earlier research has shown that diagnostic properties for screening
measures are often inflated as cutoffs are usually established post-hoc, and screening measures
therefore typically show much poorer properties in replication samples than in the original
samples (Ehring et al., 2007). In contrast to this observation, the J-PTSD showed comparable
results in the original sample (Van Dam et al., 2010), and the independent cross-validation in the
current sample, which further supports the validity of the findings.
The higher specificity of the J-PTSD compared with our former study can possibly be
explained by a difference in procedure. For instance, in the former study participants were told
that general psychological complaints were the subject of investigation, while in the current study
participants knew that the research was about symptoms originating from traumatic experiences
in the past. This might have led to a better comprehension of the items of the J-PTSD preventing
participants from overreporting symptoms. One could argue that the measurement in the current
study may therefore be slightly biased. On the other hand, we think that being transparent to
patients about the purposes of a screener better resembles good clinical practice. If implemented
in routine clinical practice, screening for PTSD should also be done in a transparent way by
providing clients with information about the purpose and procedure of the screening, offering
psycho-education regarding the relationship between PTSD and SUD, and assuring clients
consent before screening for trauma and PTSD. The modification can therefore also been seen as
a strength of the study. Additional strengths of the current study were the use of a sample of
consecutive patients, which rules out a selection bias, and the relatively large sample size.
Finally, the fact that the screening questionnaire was given while patients were still using
substances, is also a positive feature of the current study, as this mirrors daily clinical practice.
This study also had some limitations. Similar to our former study, the base rate of PTSD
was somewhat lower in our sample compared with other studies in SUD samples (Harrington &
Newman, 2007; Kimerling et al., 2006). Perhaps this difference can partly be explained by our
procedure where interviewers were blinded regarding the scores of the screener to prevent
response bias from the interviewers. Another explanation for the lower PTSD base rate may be
the use of SCID-I for assessing PTSD instead of the Clinician-Administered PTSD Scale (CAPS)
(Blake et al., 1990), which is often referred to as the gold standard. Unlike the CAPS, SCID-I
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does not include a systematic protocol for assessing the experience of traumatic events in the
past. Possibly this has led to an underestimation of PTSD diagnoses in our sample. However,
both instruments have shown a high correspondence in establishing PTSD diagnoses (Foa, &
Tolin, 2000).
Furthermore, specific sample characteristics may play a role in our former and current
study, limiting the generalizability of our findings. First, the participants have attained on average
a relatively high level of education. Although findings are mixed on whether education level is a
significant predictor of posttraumatic stress (Martz, Birks, & Blackwell, 2005), the possibility of
a negative relationship between PTSD and level of education should be considered for the Dutch
population, as a study among Dutch pregnant women showed that PTSD was significantly
associated with a lower educational level (Engelhard, van den Hout, & Schouten, 2006). Second,
our sample consisted of more men than women, whereas women apparently have a higher
vulnerability for PTSD (Olff, Langeland, Draijer, & Gersons, 2007). Third, risk of developing
PTSD after experiencing trauma might be somewhat lower in Dutch populations (Bronner et al.,
2009) when compared to the US population (Kessler, Sonnega, Bromet, Hughes, & Nelson,
1995). In addition, PTSD treatments are readily available for individuals living in the Netherlands
and paid for by national health care insurance. This may lead to a relatively early detection and
treatment of PTSD, before secondary substance abuse is developed. Differences in mental health
care systems make it difficult to compare clients with comorbid SUD and PTSD attending
treatment. Therefore, the diagnostic properties of the J-PTSD need to be cross-validated in other
countries and/or settings before their use in these different contexts can be recommended.
The generalizability of our findings is furthermore limited by the fact that we investigated
a group of SUD patients who applied for cognitive behavioral treatment. As a consequence the
more severe group of chronic care patients, participating in harm-reduction programs, was left
out. Future research is needed to test whether the results can be replicated in the more severe
group of chronic care patients.
To conclude, results of the current study suggest that the J-PTSD can be a useful
screening instrument for PTSD in a civilian SUD population. In our study, the J-PTSD showed a
good sensitivity, specificity, and OE. This finding has important clinical implications as
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screening for PTSD among SUD patients during pre-treatment assessment is crucial to ascertain
appropriate treatment allocation for SUD-patients suffering from PTSD-diagnosis.
In order to implement the PTSD screening questionnaire into clinical practice information
should be given about the existence of this tool and its proper use across substance abuse
treatment centers. Moreover it is important to create more awareness among clinicians about the
high prevalence of comorbid PTSD and SUD, the functional relationship of both disorders, and
the effectiveness of psycho-education and concurrent treatments to illustrate the advantages of
screening for PTSD among SUD patients.
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Olff, M., Langeland, W., Draijer, N., & Gersons, B. (2007). Gender differences in posttraumatic
stress disorder. Psychological Bulletin, 133, 183-204.
Ouimette, P., Goodwin, E., & Brown, P. J. (2006). Health and well being of substance use
disorder patients with and without posttraumatic stress disorder. Addictive Behaviors, 31,
1415-1423.
Ouimette, P., Brown, P. J., & Najavits, L. M. (1998). Course and treatment of patients with both
substance use and posttraumatic stress disorders. Addictive Behaviors, 23, 785-795.
Prins, A., Ouimette, P., Kimerling, R., Cameron, R. P., Hugelshofer, D. S., Shaw-Hegwer, J., et
al. (2003). The primary care PTSD screen (PC-PTSD): development and operating
characteristics. Primary Care Psychiatry, 9, 9-14.
Reynolds, M., Mezey, G., Chapman, M., Wheeler, M., Drummond, C., & Baldacchino, A.
(2005). Co-morbid post-traumatic stress disorder in a substance misusing clinical
population. Drug & Alcohol Dependence, 77, 251-258.
Saladin, M. E., Brady, K. T., Dansky, B. S., & Kilpatrick, D. G. (1995). Understanding
Comorbidity between Ptsd and Substance Use Disorders - 2 Preliminary Investigations.
Addictive Behaviors, 20, 643-655.
Saladin, M. E., Drobes, D. J., Coffey, S. F., Dansky, B. D., Brady, K. T., & Kilpatrick, D. G.
(2003). PTSD symptom severity as a predictor of cue-elicited drug craving in victims of
violent crime. Addictive Behaviors 28, 1611-1629.
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Shipherd, J. C., Stafford, J., & Tanner, L. R. (2005). Predicting alcohol and drug abuse in Persian
Gulf War veterans: What role do PTSD symptoms play? Addictive Behaviors, 30, 595-
599.
Stewart, S. H., & Conrod, P. J. (2003). Psychosocial models of functional associations between
posttraumatic stress disorder and substance use disorder. In P. Ouimette & P. J. Brown
(Eds.), Trauma and substance abuse: Causes, consequences, and treatment of comorbid
disorders (pp. 29-55). Washington DC, USA: American Psychological Association.
Stewart, S. H., Conrod, P. J., Pihl, R. O., & Dongier, M. (1999). Relations between posttraumatic
stress symptom dimensions and substance dependence in a community-recruited sample
of substance-abusing women. Psychology of Addictive Behaviors, 13, 78-88.
Van Dam, D., Ehring, T., Vedel, E., & Emmelkamp, P. M. G. (2010). Validation of the Primary
Care Posttraumatic Stress Disorder screening questionnaire (PC-PTSD) in civilian
substance use disorder patients. Journal of Substance Abuse Treatment, 39, 105-113.
Van Dam, D., Vedel, E., Ehring, T., & Emmelkamp, P. M. G. (2012). Psychological treatments
for concurrent posttraumatic stress disorder and substance use disorder: A systematic
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CChapter 4
Psychological treatments for concurrent posttraumatic
stress disorder and substance use disorder: a systematic
review
Van Dam, D., Vedel, E., Ehring, T., & Emmelkamp, P. M. G. (2012). Psychological treatments for concurrent
posttraumatic stress disorder and substance use disorder: A systematic review. Clinical Psychology Review, 32, 202-
214.
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Abstract
This article gives an overview of research into psychological treatments for concurrent
posttraumatic stress disorder (PTSD) and substance used disorder (SUD), with a special focus on
the effectiveness of treatments addressing both disorders compared to treatments addressing one
of the disorders alone. In addition, a distinction is made between trauma-focused versus non-
trauma-focused therapies for concurrent PTSD and SUD. The databases Embase, Psychinfo,
Medline and Web of science were searched for relevant articles. In total, seventeen studies were
identified evaluating ten treatments protocols (six trauma-focused and four non-trauma-focused
treatment approaches). In general, the studies showed pre-post reductions for PTSD and/ or SUD
symptoms. Although most treatments for concurrent PTSD and SUD did not prove to be superior
to regular SUD treatments, there are some promising preliminary results suggesting that some
patients might benefit from trauma-focused interventions. However, the lack of methodologically
sound treatment trials makes it difficult to draw firm conclusions. Methodological limitations are
discussed, along with recommendations for future research.
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Introduction
The relationship between PTSD and SUD
Posttraumatic stress disorder (PTSD) and substance use disorder (SUD) are both severe
and disabling disorders causing great psychological distress. According to the current literature,
prevalence estimates for PTSD in SUD samples vary from 11% to 41% (Harrington & Newman,
2007; Ouimette, Goodwin, & Brown, 2006; Van Dam, Ehring, Vedel, & Emmelkamp, 2010).
This variation may partly be due to differences in assessment methods (e.g., questionnaire
measures versus diagnostic interviews) and differing population characteristics (e.g., men,
women, war veterans). Despite this variability of prevalence estimates, it is evident that the
occurrence of PTSD among SUD-patients is high. This has important clinical implications as
patients with concurrent PTSD and SUD show higher symptom severities and worse treatment
outcomes compared to patients with either disorder alone (Back et al., 2000; Brown & Wolfe,
1994; Najavits, Weiss, & Shaw, 1999; Ouimette, Brown, & Najavits, 1998).
A number of hypotheses have been put forward to explain the concurrence of the two
disorders. The proposes a causal relationship, where substance abuse leads
to a higher risk for traumatic experiences, increasing the chance for developing PTSD (Hien,
Cohen, & Campbell, 2005). The - suggests a reverse relationship in
that concurrent PTSD and SUD is thought to be
substances as self-medication for painful and disturbing PTSD symptoms (Khantzian, 1985;
Stewart & Conrod, 2003). Repeated self-medication may then over time lead to an automatic
association between PTSD symptoms and substance use, so that exposure to trauma reminders
and/ or the experience of PTSD symptoms can trigger craving and substance use (see Baker,
Piper, McCarthy, Majeskie, & Fiore, 2004). In addition, it has been suggested that physical
symptoms due to withdrawal of substances, such as heart beating, sweating and shivering, can
evoke traumatic memories and trigger PTSD symptoms because they are similar to the
during the traumatic experience (Stewart & Conrod, 2003). Finally,
concurrent PTSD and SUD may alternatively be due to an unknown third variable, such as a
biological vulnerability or poor coping skills, increasing the risk for developing both PTSD and
SUD independently following trauma exposure (Stewart & Conrod, 2003).
64_Untitled-2.job64_Proefschrift Debora van Dam.job
64
Patients often perceive a functional relationship between PTSD and SUD. Especially the
influence of PTSD on SUD appears to be recognized by patients (Back, Brady, Jaanimägi, &
Jackson, 2006; Brown, Stout, & Gannon-Rowley, 1998). To date, the best evidence is available
for the self-medication hypothesis as PTSD is more often a precursor of SUD than vice versa
(Stewart & Conrod, 2003). Also, the improvement of PTSD complaints appears to have a greater
effect on substance use problems than vice versa (Back, 2010). Cognitive experimental research
investigating the functional relationship of PTSD and SUD is scarce, but the studies that have
been done also support the self-medication theory. For example, it has been shown that exposure
to personalized trauma-image cues leads to an increase of reported craving (Coffey et al., 2002;
Saladin et al., 2003). Although most evidence available to date supports the self-medication
hypothesis, it is conceivable that the processes described earlier are not mutually exclusive but
actually interacting with each other in the development of concurrent PTSD and SUD. Patients
with concurrent PTSD and SUD may then end up in a vicious circle, where PTSD symptoms
trigger substance abuse, substance abuse in turn increases the risk for future traumatic
experiences, and withdrawal from substances can trigger PTSD symptoms (Stewart & Conrod,
2003).
Implications for clinical practice
In sum, both retrospective and experimental research appears to confirm a functional
relationship between PTSD and SUD. This may explain the worse treatment outcomes in patients
with concurrent PTSD and SUD in current clinical practice. Traditionally, a patient with both
diagnoses is referred to a substance abuse treatment center to deal with the substance abuse first.
However, the functional relationship between PTSD and SUD suggests that PTSD symptoms will
exacerbate when substances are withheld. This puts patients in danger of dropping out during
detoxification and SUD treatment, which prevents them from receiving PTSD treatment. Psycho-
education about the vicious circle of PTSD and SUD may prepare patients with concurrent PTSD
and SUD for oncoming difficulties during detoxification and SUD treatment (Ford, Russo, &
Mallon, 2007). In addition, a number of authors have suggested that this patient group may
benefit from an integrated treatment approach that includes specific interventions for both
65_Untitled-2.job65_Proefschrift Debora van Dam.job
65
disorders (Bradizza, Stasiewicz, & Paas, 2006; Donovan, Padin-Rivera, & Kowaliw, 2001; Ford
et al., 2007; McGovern et al., 2009; Najavits et al., 2007).
Our clinical impression, shared by other researchers, is that SUD therapists commonly
hesitate to ask about traumatic experiences because they fear opening leading
patients to decompensate during treatment (Hien, Cohen, Miele, Litt, & Capstick, 2004).
Consequently, research has shown a low detection rate of PTSD within substance abuse treatment
centers as patients often do not report traumatic experiences and PTSD symptoms spontaneously
(Kimerling, Trafton, & Nguyen, 2006; Reynolds et al., 2005). It appears that systematic screening
can lead to a four times higher detection rate of PTSD among patients attending substance abuse
treatment centers (Kimerling et al., 2006; Van Dam et al., 2010). It therefore appears important to
make therapists more aware of the prevalence of concurrent PTSD and SUD and the functional
relationship between both disorders.
Before focusing on the integrated interventions for comorbid SUD and PTSD, we will
first briefly summarize the state-of-the-art of evidence-based psychological interventions for
SUD and PTSD when treated separately.
Evidence-based treatments for SUD. Cognitive behavioral treatments (CBT) are
considered evidence-based interventions for SUD. Empirically supported cognitive behavioral
approaches include coping skills training, relapse prevention, contingency management, and
behavioral couples therapy (Emmelkamp & Vedel, 2006). Coping skills training and relapse
prevention focus on recognizing and coping with high-risk situations that precipitate substance
use, and on providing patients with new strategies and skills through modeling, behavioral
practice and homework assignments (Monti, Kadden, Rohsenow, Cooney, & Abrams, 2002).
Contingency management is based on the principle of operant conditioning (Jones, Wong, Tuten,
& Stitzer, 2005; Lussier, Heil, Mongeon, Badger, & Higgins, 2006). Behavior that facilitates
abstinence is reinforced by giving patients meaningful privileges (e.g., an employment program,
rent-free housing, money). If patients do not commit themselves to the desired behavior, these
privileges are withheld as a form of punishment. Behavioral couples training focuses not only on
developing self control and coping skills of the patient, but also aims to improve the coping skills
of the spouse in order to support the patient in gaining treatment goals (Powers, Vedel, &
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66
Emmelkamp, 2008). It additionally focuses on social functioning of the couple in their
relationship and in their social network.
Another type of treatment intervention for SUD (not based on CBT) is the twelve-step
treatment approach (Alcoholics Anonymous) (Emmelkamp & Vedel, 2006). An important
characteristic of the twelve-step philosophy is the aim to stimulate a sense of spirituality in
participants in order to give them meaning in life. Other important principles are the idea that
substance abuse is a chronic disease, and that therefore the only way to tackle this disease is by
striving for total life-time sobriety. In order to accomplish this treatment goal, participants are
stimulated to build an alcohol- and drugfree social environment around them. The treatment
results of the twelve-step approaches are comparable to other evidence-based treatments for
alcohol use disorder (Ferri, Amato, & Davoli, 2006).
Evidence-based treatments for PTSD. Treatment approaches for PTSD are often
divided into trauma-focused versus non-trauma-focused treatments (e.g., Bisson et al., 2007).
Trauma-focused treatments are defined as focusing on the memory of the traumatic event and its
meaning (see National Collaborating Centre for Mental Health, 2005). Two different types of
trauma-focused treatment are exposure-based therapies and eye movement desensitization and
reprocessing (EMDR). The main ingredient of exposure-based therapies is imaginal exposure,
which is often combined with in vivo exposure (Powers, Halpern, Ferenschak, Gillihan, & Foa,
2010). During imaginal exposure, patients are asked to revisit their traumatic event in their
imagination and describe it in great detail. In vivo exposure consists of repeated exposure to
trauma-related real-life situations patients have been avoiding since the trauma. In EMDR, the
client is instructed to focus on the traumatic memory and simultaneously perform rhythmic eye
movements or other bilateral stimulation (Shapiro, 1995).
Results of most meta-analyses suggest equal efficacy for exposure-based therapies and
eye movement desensitization and reprocessing (EMDR) (Bisson et al., 2007; Bradley, Greene,
Russ, Dutra, & Westen, 2005; Seidler & Wagner, 2006). In current clinical guidelines, both
exposure-based therapies and EMDR are therefore recommended as first-line treatments for
PTSD (e.g., National Collaborating Centre for Mental Health, 2005). However, other reports
have suggested that evidence is still inadequate to determine the efficacy of EMDR (Institute of
67_Untitled-2.job67_Proefschrift Debora van Dam.job
67
Medicine, 2008). In sum, the best evidence currently exists for exposure-based therapies
(Institute of Medicine, 2008).
Non-trauma-focused therapies for PTSD focus on the present or past aspects of the
and do not require patients to revisit or reprocess the trauma.
The aim of this group of treatments is to provide patients with coping skills to manage their
trauma symptoms and to improve functioning. Examples of non-trauma-focused therapies are
stress management, supportive/ non-directive therapy and relaxation (Foa, Keane, & Friedman,
2008). Only limited and inconsistent evidence has been found for non-trauma-focused CBT,
stress management and relaxation in the treatment of PTSD (Bisson et al., 2007). Therefore,
current clinical guidelines recommend against routinely offering this kind of treatments to trauma
survivors who present with chronic PTSD (e.g., National Collaborating Centre for Mental Health,
2005).
Purpose of this review
In sum, the prevalence of concurrent PTSD and SUD is high. Concurrent PTSD and SUD
has been associated with higher symptom severities and worse treatment outcomes. A number of
authors have suggested a functional relationship between both disorders, which is largely
supported by empirical evidence. The current clinical practice of sequentially treating both
disorders might contribute to worse treatment outcomes as a sequential approach does not address
the mutual relationship between the two disorders. Therefore, several authors have proposed that
concurrent treatment for both disorders may be more effective for this patient group.
In recent years, a number of treatment models and protocols for combined treatment of
PTSD and SUD have been developed, tested and implemented into clinical practice. However,
treatment rationales, types of intervention used, and treatment intensities are strikingly different
between the different programs. The purpose of this review is (1) to give an overview of
psychological treatments that have been developed and evaluated for treating concurrent PTSD
and SUD, and (2) to summarize the existing evidence for the hypothesis that treatments
simultaneously targeting PTSD and SUD are more effective than treatments focusing on one of
the disorders alone.
68_Untitled-2.job68_Proefschrift Debora van Dam.job
68
We are aware of two earlier qualitative reviews focusing on treatment for comorbid PTSD
and SUD (McCarthy & Petrakis, 2010; Souza & Spates, 2008). However, an update of these
reviews appears timely as a number of studies have been published since. In addition, our article
extends these earlier ones by using more stringent criteria for the inclusion of studies and by
making a distinction between trauma-focused and non-trauma-focused PTSD treatments, which is
in line with the PTSD literature (e.g., Bisson et al., 2007). In addition, we only include studies
using research samples with a formal diagnosis for PTSD and SUD.
Method
In order to identify relevant articles, the databases Embase, Psychinfo, Medline and Web of
science were searched combining the keywords PTSD, substance use disorder and treatment as
well as their synonyms1. The databases were searched for articles published by January 2011.
Articles were included in the current review if (1) they were published in a peer-reviewed
journal, (2) they were published in English, (3) they described studies investigating the
effectiveness of psychological treatments specifically developed for treating concurrent PTSD
and SUD, (4) the studied sample had a formal diagnosis for (full-blown or partial) PTSD and
SUD, and (5) the dependent variables included PTSD symptoms and SUD symptoms. Studies not
reporting the percentage of participants meeting a formal diagnosis for (partial or full-blown
PTSD) or for SUD were excluded. The selection process of relevant articles is illustrated in
Figure 1.
The database search led to 1952 hits. Abstracts of all studies that were identified as
relevant and were retrieved for more detailed information in the first selection (N = 163) were
1 Databases (Embase, Psychinfo, Medline and Web of science) were searched with the following key words: (PTSD or posttraumatic or post-traumatic) AND (treatment or intervention* or randomized controlled trial or RCT or therap*) AND (addiction or SUD or substance-related disorders or substance abuse or substance dependence or alcohol abuse or alcohol dependence or drug abuse or cocaine abuse or cocaine dependence or opioids abuse or opioids dependence or cannabis abuse or cannabis dependence or sedative abuse or sedative dependence or hypnotic abuse or hypnotic dependence or anxiolytic abuse or anxiolytic dependence or polydrug abuse or polydrug dependence).
69_Untitled-2.job69_Proefschrift Debora van Dam.job
69
Figure 1. Flow-chart for the selection of relevant articles
References retrieved for more detailed information (N = 163)
References excluded that did not address specifically developed treatments for concurrent PTSD and SUD (N =1,789)
References excluded that did not address treatment effectiveness or relevant dependent variables (N = 132)
References excluded that did not address psychological, but pharmacological treatments for PTSD and SUD (N = 3)
Potentially relevant references identified and screened for retrieval (N = 1,952)
Potentially appropriate references retrieved for more detailed information (N = 31)
References excluded that were not published in journals or in languages other than English (N = 5)
References with usable information (N = 17)
References excluded that did not include a formal diagnosis for PTSD or SUD (N = 6)
70_Untitled-2.job70_Proefschrift Debora van Dam.job
70
independently evaluated by two of the authors. If an abstract appeared to represent a relevant
article, the full report was read by each reviewer independently to determine if the study met the
inclusion criteria. In the second round, 132 of the 163 references were excluded from this review
because they either did not report treatment outcome data at all or did not include dependent
variables of relevance for the current study. In the third round, 14 of the 31 potentially
appropriate studies identified in the second round were excluded; one study was excluded
because results were only published in the Norwegian language (Amundsen & Kårstad, 2006).
Description of the study in the English abstract suggests that the article described an uncontrolled
study of 20 clients receiving EMDR. Four studies were excluded because they had exclusively
been published as dissertations (Bragdon, 2007; Caldeira, 2004; Lester et al., 2007; Stiffler,
2006). In addition, three studies evaluating pharmacological treatments for patients with a
concurrent PTSD and SUD were excluded from this review (Brady et al., 2005; Brady, Sonne, &
Roberts, 1995; Petrakis et al., 2006). Finally, six studies were excluded because either no formal
diagnosis for SUD (Steindl, Young, Creamer, & Crompton, 2003) or no formal diagnosis for
(full-blown or partial) PTSD was established in these studies (Amaro et al., 2007; Covington,
Burke, Keaton, & Norcott, 2008; Gatz et al., 2007; Messina, Grella, Cartier, & Torres, 2010;
Toussaint, VanDeMark, Bornemann, & Graeber, 2007). The following treatment approaches
were investigated in these studies: Trauma Recovery and Empowerment (TREM) (Harris, 1998),
Helping Women Recover (HWR) and Beyond Trauma (BT) (Covington et al., 2008), Seeking
Safety therapy (SS) (Najavits, 2003), and CBT for alcohol misuse added on trauma-focused CBT
for PTSD (Steindl et al., 2003). Table 1 gives an overview of all studies investigating
psychological treatments for PTSD and SUD that were excluded from the current review. The 17
studies included in the review are presented in Table 2 and 3.
Treatments for concurrent PTSD and SUD
In the PTSD treatment literature, an important distinction is commonly made between
trauma-focused and non-trauma-focused treatments. In the current review, the presentation of the
studies is therefore structured according to this distinction. In addition, combined treatments have
been developed in different ways. Some therapies encompass one specifically designed stand-
alone treatment protocol, in which PTSD and SUD interventions are combined. This kind of
71_Untitled-2.job71_Proefschrift Debora van Dam.job
71
Tab
le 1
. E
xclu
ded
Stud
ies
Inve
stig
atin
g P
sych
olog
ical
Tre
atm
ents
for
PT
SD a
nd S
UD
.
Stud
y T
reat
men
t(s)
N
umbe
r of
se
ssio
ns/ t
ype
of t
reat
men
t
Des
ign
N
Sam
ple
Rea
son
fo
r
excl
usio
n
Mea
- su
re(s
) P
TSD
Mea
- su
re(s
) SU
D
Mea
- su
re(s
) T
imin
g
PT
SD
wit
hin
gr
oup
ef
fect
s
PT
SD
betw
een
grou
p
effe
cts
SUD
w
ithi
n
grou
p
effe
cts
SUD
be
twee
n gr
oup
ef
fect
s A
mar
o et
al.
(200
7)
A)
TR
EM
& T
AU
ve
rsus
B)
TA
U
25/ g
roup
Q
uasi
E
xper
imen
tal
342
wom
en
No
form
al
diag
nosi
s PT
SD
PSS
AS
I Pr
e 6m
onth
12
mon
th
(pos
t ba
selin
e)
A+
B
n/r
A
> B
A
+
B+
A=
B/
A>
B2
Cov
ingt
on e
t al.
(200
8)
A)
HW
R a
nd B
T
28/ g
roup
U
ncon
trol
led
79
wom
en
No
form
al
diag
nosi
s PT
SD
TSC
-40
A
SI-
F
Pre-
post
/ d
urin
g tr
eatm
ent
A +
n/
a A
+
n/a
Gat
z et
al.
(200
7)
A)
SS &
TA
U
vers
us B
) T
AU
31/ g
roup
Q
uasi
E
xper
imen
tal
313
wom
en
No
form
al
diag
nosi
s PT
SD
PSS
AS
I Pr
e-po
st
3mon
th
6mon
th
9mon
th
12m
onth
A +
B
+
A>
B
A +
B
+
A=
B
Mes
sina
et a
l. (2
010)
A)
HW
R a
nd B
T
vers
us B
) T
AU
28/ g
roup
RC
T
115
wom
en/
inca
rce-
rate
d
No
form
al
diag
nosi
s PT
SD
PDS
A
SI-
Lit
e Pr
e 6m
onth
12
mon
th
n/r
n/r
A +
A
> B
Stei
ndl e
t al.
(200
3)
A)
Com
bina
tion
of
2 C
BT
trea
tmen
ts f
or
PTSD
and
SU
D
4 da
ys p
er
wee
k fo
r 6
wee
ks &
1- 2
da
ys p
er w
eek
for
6 w
eeks
/ gr
oup
Unc
ontr
olle
d 60
8 m
en/
vete
rans
N
o fo
rmal
di
agno
sis
SUD
PCL
A
UD
IT
Pre
3 m
onth
9
mon
th
A +
n/
a A
+
n/a
Tou
ssai
nt e
t al.
(200
7)
A)
TR
EM
& T
AU
ve
rsus
B)
TA
U
24/ g
roup
Q
uasi
E
xper
imen
tal
170
wom
en
No
form
al
diag
nosi
s PT
SD
PSS
AS
I Pr
e 6m
onth
12
mon
th
n/r
A
= B
n/r
A
= B
Not
e. P
TS
D =
Pos
ttrau
mat
ic s
tres
s di
sord
er. S
UD
= S
ubst
ance
use
dis
orde
r. T
AU
= T
reat
men
t as
usua
l. T
RE
M =
Tra
uma
Rec
over
y an
d E
mpo
wer
men
t. H
WR
and
BT
= H
elpi
ng W
omen
R
ecov
er a
nd B
eyon
d T
raum
a. S
S =
See
king
Saf
ety
ther
apy.
RC
T =
Ran
dom
ized
con
trol
led
tria
l. C
BT
= C
ogni
tive
beh
avio
ral t
reat
men
t. +
= s
igni
fica
nt im
prov
emen
t of
sym
ptom
s.
- =
sig
nifi
cant
wor
seni
ng o
f sy
mpt
oms.
+/-
= n
o si
gnif
ican
t cha
nge
in s
ympt
oms.
n/a
= n
ot a
pplic
able
. n/r
= n
ot r
epor
ted.
2 N
o di
ffer
ence
s fo
r al
coho
l or
drug
s se
veri
ty. H
owev
er th
e in
terv
enti
on g
roup
rep
orte
d si
gnif
ican
tly
high
er d
rug
abst
inen
ce r
ates
than
the
com
pari
son
grou
p. T
his
effe
ct w
as n
ot f
ound
for
alc
ohol
ab
stin
ence
rat
es.
72_Untitled-2.job72_Proefschrift Debora van Dam.job
72
Tab
le 2
. O
verv
iew
of I
nclu
ded
Stud
ies
Inve
stig
atin
g P
sych
olog
ical
Tre
atm
ents
for
Con
curr
ent P
TSD
and
SU
D.
Tre
atm
ent(
s)
Tra
uma-
focu
sed/
N
on-t
raum
a-fo
cuse
d E
xpos
ure
Inte
grat
ed/ a
dd-o
n SU
D
trea
tmen
t N
umbe
r of
stu
dies
(N
= 1
7)
Con
curr
ent T
reat
men
t of
PT
SD
and
C
ocai
ne D
epen
denc
e (C
TP
CD
) (l
ater
m
odif
ied
into
CO
PE
)
Tra
uma-
focu
sed
Imag
inal
In
viv
o In
tegr
ated
C
BT
N
= 1
(B
ack
et a
l., 2
001)
Imag
inal
Exp
osur
e (I
E)
T
raum
a-fo
cuse
d Im
agin
al
Add
-on
Cop
ing
skil
ls-
base
d th
erap
y N
= 1
(C
offe
y et
al.,
200
6)
M
ultip
le C
hann
el E
xpos
ure
Tra
inin
g (M
CE
T)
Tra
uma-
focu
sed
Imag
inal
In
viv
o A
dd-o
n 12
-ste
p C
BT
N
= 1
(D
avis
et a
l. 20
05)
(cas
e st
udy)
Imag
e H
abit
uatio
n T
rain
ing
(IH
T)
Tra
uma-
focu
sed
Imag
inal
-
n/
r N
= 1
(V
augh
an &
Tar
rier
199
2) (
case
stu
dy)
E
xpos
ure
The
rapy
Tra
uma-
focu
sed
Imag
inal
In
vivo
- -
N =
1 T
uerk
et a
l. 20
09 (
case
stu
dy)
Seek
ing
Saf
ety
ther
apy
plus
Exp
osur
e T
hera
py-r
evis
ed
Tra
uma-
focu
sed
Imag
inal
In
tegr
ated
C
BT
N
= 1
(N
ajav
its,
et a
l. 20
05)
(pil
ot)
Seek
ing
Saf
ety
ther
apy
(SS)
Non
-tra
uma-
focu
sed
- In
tegr
ated
C
BT
N
= 8
(C
ohen
& H
ien,
200
6; C
ook
et a
l., 2
006;
Hie
n et
al.,
20
04; H
ien
et a
l., 2
009;
Kill
een
et a
l., 2
008;
Naj
avits
et a
l.,
2006
; Naj
avit
s et
al.,
199
8; N
orm
an e
t al.,
201
0; Z
lotn
ick
et a
l., 2
009;
Zlo
tnic
k et
al.,
200
3)
C
BT
for
PT
SD in
add
ictio
n tr
eatm
ent
prog
ram
s (C
BT
-P in
add
)
Non
-tra
uma-
focu
sed
- A
dd-o
n C
BT
N
= 1
(M
cGov
ern
et a
l., 2
009)
Sub
stan
ce D
epen
denc
y-P
ost-
trau
mat
ic
stre
ss d
isor
der
The
rapy
(SD
PT
)
Non
-tra
uma-
focu
sed
In v
ivo
Inte
grat
ed
CB
T
N =
1 (
Tri
ffle
man
, 200
0)
Tra
nsce
nd
N
on-t
raum
a-fo
cuse
d So
cial
sh
arin
g
Inte
grat
ed
Ecl
ectic
N
= 1
(D
onov
an e
t al.,
200
1)
Not
e. n
/r =
not
rep
orte
d. P
TSD
= P
osttr
aum
atic
str
ess
diso
rder
. SU
D =
Sub
stan
ce u
se d
isor
der.
CB
T =
Cog
nitiv
e be
havi
oral
trea
tmen
t.
73_Untitled-2.job73_Proefschrift Debora van Dam.job
73
Tab
le 3
. Stu
dies
Eva
luat
ing
Non
-tra
uma-
focu
sed
Tre
atm
ents
.
Stud
y T
reat
men
t(s)
N
umbe
r of
se
ssio
ns/
type
of
trea
tmen
t
Des
ign
N
Sam
ple
PT
SD3
%
Mea
- su
re(s
) P
TSD
Mea
- su
re(s
) SU
D
Mea
- su
re(s
) T
imin
g
PT
SD
wit
hin
gr
oup
ef
fect
s
PT
SD
betw
een
grou
p
effe
cts
SUD
w
ithi
n
grou
p
effe
cts
SUD
be
twee
n gr
oup
ef
fect
s C
ohen
et a
l. (2
006)
H
ien
et a
l. (2
004)
A)
SS &
CC
ve
rsus
B
) R
P &
CC
ve
rsus
C
) C
C
24/
indi
vidu
al
RC
T
10
7 w
omen
88%
CA
PS
IES
C
GI
SUI
CG
I
Pre-
post
6m
onth
9m
onth
A +
B
+
C +
/-
A=
B
A>
C
B>
C
(A+
B)
>C
A +
B
+
C +
/-
A=
B
A>
C
B>
C
(A+
B)
>C
Coo
k et
al.
(2
006)
A)
SS
25/
grou
p
Unc
ontr
olle
d
25
men
and
w
omen
/ ve
tera
ns
100%
4 PC
L-M
da
ys o
f ab
sti-
nenc
e
Pre-
post
A
+
n/a
A +
/-5
n/
a
Don
ovan
et a
l. (2
001)
A
) T
rans
cend
12-w
eeks
, 10
hour
s a
wee
k/ g
roup
Unc
ontr
olle
d 46
m
en/
vete
rans
10
0%
CA
PS
AS
I Pr
e-po
st6
6mon
th
12m
onth
A +
n/
a A
+
n/a
Hie
n et
al.
(2
009)
K
ille
en e
t al.
(200
8)
A)
SS &
TA
U
vers
us
B)
WH
E &
TA
U
12/
grou
p
RC
T
353
wom
en
80
%
C
APS
PS
Sr
days
of
abst
i-ne
nce
Pre-
post
6m
onth
9m
onth
12
mon
th
A +
B
+
A=
B
A
+/-
B
+/-
A
= B
McG
over
n et
al.
(200
9)
A)
CB
T-P
in a
dd
8-12
/ in
divi
dual
U
ncon
trol
led
15
men
10
0%
CA
PS
AS
I
Pre-
post
3m
onth
A
+
n/a
A +
7 n/
a
Naj
avits
, et a
l. (1
998)
A
) SS
24
/ gr
oup
U
ncon
trol
led
27
w
omen
100%
T
SC-4
0 M
PSSR
A
SI
SUI
Pre-
post
3m
onth
A
+8
n/a
A +
n/
a
Naj
avits
et a
l. (2
006)
A
) SS
& C
C
vers
us
B)
CC
25/
indi
vidu
al
RC
T
33
girl
s
100%
W
AS
PE
I B
SU
RFU
Pre-
post
3m
onth
A
+
B n
/r
A>
B
A +
B
n/r
A
> B
Not
e. P
TSD
= P
ostt
raum
atic
str
ess
diso
rder
. SU
D =
Sub
stan
ce u
se d
isor
der.
SS
= S
eeki
ng S
afet
y th
erap
y. C
C=
sta
ndar
d C
omm
unit
y C
are.
RP
= R
elap
se P
reve
ntio
n. T
AU
= T
reat
men
t as
us
ual.
WH
E =
WH
ealth
Edu
catio
n. C
BT
= C
ogni
tive
beha
vior
al tr
eatm
ent.
CB
T-P
in a
dd =
CB
T f
or P
TSD
in a
ddic
tion
trea
tmen
t pro
gram
s. S
DP
T =
Sub
stan
ce D
epen
denc
y P
ost-
tr
aum
atic
str
ess
diso
rder
The
rapy
. RC
T =
Ran
dom
ized
con
trol
led
tria
l. +
= s
igni
fica
nt im
prov
emen
t of
sym
ptom
s. -
= s
igni
fica
nt w
orse
ning
of
sym
ptom
s. +
/- =
no
sign
ific
ant c
hang
e
in s
ympt
oms.
n/a
= n
ot a
pplic
able
. n/r
= n
ot r
epor
ted.
3 T
he p
erce
ntag
e of
ful
l-bl
own
PT
SD in
the
rese
arch
sam
ple.
The
per
cent
age
of s
ubth
resh
old
PT
SD
can
be
deri
ved
from
the
com
plem
ent (
100%
).
4 C
lini
cian
dia
gnos
ed.
5 C
onti
nued
abs
tinen
ce f
rom
sub
stan
ces
pre-
to p
ost.
6 D
isch
arge
AS
I da
ta w
ere
not c
olle
cted
.
7 N
o si
gnif
ican
t dec
reas
es in
num
ber
of d
ays
drin
king
or
usin
g dr
ugs,
but
a s
igni
fica
nt d
ecre
ase
in r
epor
ted
SU
D-s
ever
ity.
8
Ref
erri
ng to
impr
ovem
ent i
n tr
aum
a-re
late
d sy
mpt
oms,
sym
ptom
atic
74_Untitled-2.job74_Proefschrift Debora van Dam.job
74
Tab
le 3
(co
ntin
ued)
. Stu
dies
Eva
luat
ing
Non
-tra
uma-
focu
sed
trea
tmen
ts.
Stud
y T
reat
men
t(s)
N
umbe
r of
se
ssio
ns/
type
of
trea
tmen
t
Des
ign
N
Sam
ple
PT
SD9
%
Mea
- su
re(s
) P
TSD
Mea
- su
re(s
) SU
D
Mea
- su
re(s
) T
imin
g
PT
SD
wit
hin
gr
oup
ef
fect
s
PT
SD
betw
een
grou
p
effe
cts
SUD
w
ithi
n
grou
p
effe
cts
SUD
be
twee
n gr
oup
ef
fect
s N
orm
an e
t al.
(201
0)
A)
SS
10/
grou
p
Unc
ontr
olle
d 14
m
en/
vete
rans
10
100%
PC
L-M
A
udit
DA
ST
Pr
e-po
st
3mon
th
6mon
th
A11
n/
a A
12
n/a
Tri
ffle
man
(2
000)
A
) SD
PT
ve
rsus
B
) 12
step
40/
indi
vidu
al
RC
T (
pilo
t)
19
men
and
w
omen
44
%
men
70
%
wo-
men
CA
PS
AS
I Pr
e / d
urin
g tr
eatm
ent
1mon
th
(A +
B)
13 +
A=
B
(A
+
B)14
+
A=
B
Zlo
tnic
k et
al.
(2
003)
A)
SS &
TA
U
24/ g
roup
U
ncon
trol
led
17
wom
en/
inca
rce-
rate
d
100%
C
APS
A
SI
SC
ID
Pre-
post
3m
onth
A
+
n/a
A +
n/
a
Zlo
tnic
k et
al.
(200
9)
A)
SS &
TA
U
vers
us
B)
TA
U
18-2
4/ g
roup
&
12/
in
divi
dual
RC
T
49
wom
en/
inca
rce-
rate
d
84%
C
APS
-I
TSC
-40
TH
Q
AS
I
TL
FB
Pre-
post
3m
onth
6m
onth
A +
B
+
A=
B
A
+
B +
A
= B
N
ote.
PT
SD
= P
osttr
aum
atic
str
ess
diso
rder
. SU
D =
Sub
stan
ce u
se d
isor
der.
SS
= S
eeki
ng S
afet
y th
erap
y. C
C =
sta
ndar
d C
omm
unity
Car
e. R
P =
Rel
apse
Pre
vent
ion.
TA
U =
Tre
atm
ent a
s us
ual.
WH
E =
WH
ealth
Edu
catio
n. C
BT
= C
ogni
tive
beha
vior
al tr
eatm
ent.
CB
T-P
in a
dd =
CB
T f
or P
TSD
in a
ddic
tion
trea
tmen
t pro
gram
s. S
DP
T =
Sub
stan
ce D
epen
denc
y P
ostt
raum
atic
str
ess
diso
rder
The
rapy
. RC
T =
Ran
dom
ized
con
trol
led
tria
l. +
= s
igni
fica
nt im
prov
emen
t of
sym
ptom
s. -
= s
igni
fica
nt w
orse
ning
of
sym
ptom
s. +
/- =
no
sign
ific
ant c
hang
e in
sy
mpt
oms.
n/a
= n
ot a
pplic
able
. n/r
= n
ot r
epor
ted.
9 T
he p
erce
ntag
e of
ful
l-bl
own
PT
SD in
the
rese
arch
sam
ple.
The
per
cent
age
of s
ubth
resh
old
PT
SD
can
be
deri
ved
from
the
com
plem
ent (
100%
).
10 P
TSD
- an
d SU
D-d
iagn
oses
wer
e ba
sed
on th
e in
take
with
a m
enta
l hea
lth p
rovi
der
11 1
2 C
hang
es w
ere
exam
ined
on
an in
divi
dual
bas
is.
13 14
With
in g
roup
eff
ects
wer
e on
ly r
epor
ted
for
the
sam
ple
as a
who
le, a
nd n
ot s
peci
fied
for
trea
tmen
t A o
r B
.
75_Untitled-2.job75_Proefschrift Debora van Dam.job
75
treatment protocols will be referred to as integrated treatments. In the other protocols, the
original treatment for SUD is maintained, while a separate therapy targeting PTSD is added to the
SUD treatment. These treatment protocols will be referred to as add-on treatments. Most of the
SUD interventions used in the combined treatment programs can be considered as evidence-
based interventions for SUD.
Non-Trauma-Focused Therapies
In the following, four non-trauma-focused treatment programs will be described in more
detail and their treatment effectiveness will be discussed (see Tables 2 and 3). These programs
are Seeking Safety therapy (SS) (Najavits, 2003), CBT for PTSD in SUD treatment (McGovern
et al., 2009), Substance Dependency-Posttraumatic stress disorder Therapy (SDPT) (Triffleman,
Carroll, & Kellogg, 1999) and Transcend (Donovan et al., 2001). First, the eight studies
investigating the effectiveness of SS will be presented, followed by one study investigating the
effectiveness of CBT for PTSD in SUD treatment, one study evaluating the effectiveness of
SDPT, and one study investigating the effectiveness of Transcend (see Table 3).
Seeking Safety therapy. Seeking Safety therapy (SS) is the treatment approach for
patients with PTSD and SUD that has most extensively been studied to date. It incorporates a
combination of non-trauma-focused CBT for PTSD and CBT for SUD. SS aims to educate
patients about both disorders and assist them in developing self-control skills to prevent drug use
and to manage overwhelming affect. Another important element of the treatment is cognitive
promoting participants to build a supportive network. An important assumption in SS is that
safety has the highest priority when recovering from both disorders. Safety is defined as
n in self-destructive behavior, establishment of a
network of supportive people, and self-protection from dangers associated with the disorders
(e.g., HIV- (Najavits, Weiss, Shaw, & Muenz, 1998, p. 439). Of the
eight studies investigating the effectiveness of SS, four were uncontrolled studies and four were
randomized controlled trials (RCTs). Although SS was originally designed as an integrated stand-
alone treatment, SS has also been evaluated as an add-on to SUD treatment.
76_Untitled-2.job76_Proefschrift Debora van Dam.job
76
The four uncontrolled studies comprise diverse population samples (women, incarcerated
women, men and male veterans; N between 14 and 27) (Cook, Walser, Kane, Ruzek, & Woody,
2006; Najavits et al., 1998; Norman, Wilkins, Tapert, Lang, & Najavits, 2010; Zlotnick, Najavits,
Rohsenow, & Johnson, 2003). In addition, the number of SS therapy sessions offered varied from
10 to 30 sessions (see Table 3). In three of the studies, SS was investigated as a stand-alone
treatment (Cook et al., 2006; Najavits et al., 1998; Norman et al., 2010). In one study, SS was
investigated as an add-on to a residential therapeutic program for women in prison based on the
12-step program for addictions (Zlotnick et al., 2003). In one of the studies, PTSD and SUD were
not diagnosed with a clinical structured interview but clinical diagnoses were established by a
mental health provider at intake (Norman et al., 2010).
In all four uncontrolled studies, PTSD and SUD symptom severities were found to
significantly improve from pre- to post treatment. The three studies incorporating 3-month
follow-up measurements showed that these improvements were maintained at follow-up
(Najavits et al., 1998; Norman et al., 2010; Zlotnick et al., 2003). Completer percentages ranged
from 63% to 72% in three of the four uncontrolled studies. However, it is noteworthy that these
three studies all used different definitions of completers (Cook et al., 2006: attending 56% of the
sessions until the end of therapy; Najavits et al., 1998: attending at least 25% of the sessions;
Norman et al., 2010: completing follow-up measures). In the study among incarcerated women,
all patients completed treatment, which can be explained by the specific setting (Zlotnick et al.,
2003). Although the results appear promising, no firm conclusions can be drawn based on
uncontrolled studies alone. It is therefore important to consider the results of more
methodologically rigorous studies investigating the effectiveness of SS.
So far, four RCTs have been conducted investigating the effectiveness of SS (Hien et al.,
2004; Hien et al., 2009; Najavits, Gallop, & Weiss, 2006; Zlotnick, Johnson, & Najavits, 2009).
Hien et al. (2004) assigned 75 female PTSD-SUD patients to either 24 sessions of SS or CBT for
SUD. Both therapies were combined with TAU (community care). SS plus TAU, and CBT for
SUD plus TAU were compared to TAU alone. TAU alone was offered to a nonrandomized
control group (N = 32). Participants receiving SS plus TAU or CBT for SUD plus TAU both
showed significant and equal reductions in quantity and frequency of substance use from pre- to
post-treatment, as well as reductions in PTSD symptom severity from pre- to post-treatment. For
77_Untitled-2.job77_Proefschrift Debora van Dam.job
77
both groups improvements in substance use and PTSD severity sustained at 6-month and 9-month
follow-ups. On the other hand, the TAU group showed no significant changes regarding
substance use, and PTSD symptoms even got worse during the study interval. Overall retention
rates were 75%, whereby retention was defined as participants having attended at least 25% of all
therapy sessions. No between group differences for retention were found. When the data of SS
plus TAU and CBT for SUD plus TAU were pooled, these treatments showed significantly
stronger reductions in PTSD symptoms and substance use compared to TAU (Cohen & Hien,
2006).
Although SS resulted in significant improvements of PTSD and SUD compared to the
non-active comparison group, this RCT did not prove superiority of SS above a regular treatment
program dealing with SUD only. In addition, the high retention rates of both active treatments
should be interpreted with caution because patients were labeled as completers after attending a
relatively small number of treatment sessions.
In a small RCT with 49 incarcerated individuals with PTSD and SUD, SS was added to
treatment as usual (TAU) as a voluntary group treatment (Zlotnick et al., 2009). The SS
intervention consisted of 18 to 24 group sessions and 12 individual booster sessions. TAU was a
required residential treatment program for addiction for the duration of 3 to 6 months, based on
the 12-step model. Results for PTSD and SUD were compared between the SS plus TAU
condition and TAU alone. A comparison between retention for SS plus TAU (78%) and TAU
(100%) cannot be made because TAU was obligatory. Also, the percentage of sessions necessary
to be defined as a completer for SS was not explicitly described. Assessments took place at
intake, 12 weeks after intake (4 to 6 weeks after the end of the group SS, which was close to
), and 3 and 6 months after release from prison. Both groups showed
a significant reduction in frequency and severity of PTSD symptoms from pre-treatment, to 12
weeks after intake, and to 3 and 6 months after release from prison. Also, both groups showed
equal improvements in drug and alcohol use severity as well as in days of abstinence. Hence, the
results of this study again do not favor SS above regular SUD treatment.
In an RCT by Hien et al. (2009) (N = 353), SS was compared to an active comparison
group (WHE). Both active interventions comprised 12
group-sessions and were combined with community-based substance abuse treatment programs
78_Untitled-2.job78_Proefschrift Debora van Dam.job
78
(TAU). The seven participating treatment sites offered different kinds of TAU, differing in
length, frequency and SUD treatment orientation. Equal improvements for SS and WHE were
found in clinician-rated and self-reported PTSD symptom severity, whereas no improvements
were found for substance use in both treatments (measured by self-reported days of abstinence
and days of substance use). Overall 56% of the participants completed at least 6 treatment
sessions (50%), whereby both groups did not differ in treatment attendance. No differences
between groups were found for adverse events. Adverse events referred to the extent to which
treatment evoked negative consequences (increased PTSD symptoms, increased depression
symptoms, and increased or more severe alcohol or substance use) (Killeen et al., 2008).
In an RCT carried out among 33 PTSD-SUD adolescent girls (Najavits et al., 2006), the
SS protocol was modified by including the option to discuss details of the trauma15. SS
comprised 25 individual treatment sessions, and was combined with TAU. SS plus TAU was
compared to TAU alone. The TAU condition was similar to standard community care and not
uniform. In other words, the control group was not offered a manualized comparative treatment,
but patients were allowed to attend any concurrent treatments they naturalistically sought.
Positive outcomes were found favoring the SS condition compared to standard community care in
substance use and associated problems, some trauma-related symptoms, and cognitions related to
SUD and PTSD. The average attendance of sessions was 12. A definition of completer or
completer percentages could not be obtained from the article.
The results of the latter study appear promising. However, one should bear into mind that
SS plus TAU included more individual therapy sessions than the community care TAU condition,
which may have led to the superior treatment results. It should also be noted that the research
sample was relatively small, and that the assessment instruments in this study are not commonly
used in comparable studies (see Table 3).
In sum, both the uncontrolled studies and the repeated measure comparisons in the quasi
experimental study and the RCTs showed that SS can lead to significant improvements in SUD
and PTSD symptom severity. However, there is no evidence to date that patients with a formal
15 This treatment module can be seen as a form of trauma-focused intervention. However, the dose of this intervention appeared to be minimal (M = 1.33 sessions; SD = 2.09). Therefore, this study is discussed in the non-trauma-focused section.
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diagnosis of (partial) PTSD and SUD are more effectively treated with SS than with active
control treatments focusing on SUD only. There is preliminary evidence, however, that SS may
be superior to standard community care (Najavits et al., 2006).
When evaluating the SS studies, a number of limitations are noteworthy. First, half of the
studies carried out were uncontrolled studies. These studies lack the methodological rigor to draw
firm conclusions. Second, not all studies used the same outcome measures and treatment settings
differed largely, which makes it difficult to compare results across studies. Third, the studies used
different definitions for treatment completers, some of which appeared overly lenient. Finally, in
one RCT different kind of TAU programs were used in addition to the experimental and the
control treatment. The TAU programs varied in treatment approach, length, and intensity (Hien et
al., 2009; Killeen et al., 2008), which makes it difficult to compare treatment results even within
the same study.
CBT for PTSD in SUD treatment. McGovern et al. (2009) adapted an existing PTSD
protocol for individuals with comorbid severe mental illnesses in order to implement it in the
context of existing addiction treatment services. The PTSD treatment comprised 8 to 12
individual sessions including psycho-education, breathing re-training, and cognitive restructuring.
The SUD treatment was an intensive outpatient program focusing on psycho-education about
SUD, and learning coping skills to manage relapse. An uncontrolled study was performed to
investigate the effectiveness of CBT for PTSD in SUD treatment (N = 15). The retention rate was
65% (defined as completion of at least 75% of the treatment sessions). Completer analyses over
11 cases from baseline to post-treatment and to 3 month follow-up showed significant reductions
in PTSD diagnoses and symptom severities. There were no significant decreases in the number of
days drinking or using drugs over time, but there was a significant decrease in SUD severity.
Although results suggest an improvement for PTSD and SUD symptoms, no firm
conclusions can be drawn based on this study because of methodological limitations, especially
the uncontrolled nature of the study, the small sample size, and the use of a completer analysis
only.
Substance Dependency-Posttraumatic stress disorder Therapy. Substance
Dependency-Posttraumatic stress Disorder Therapy (SDPT) was developed as an integrated
individual treatment for PTSD and SUD (Triffleman, 2000). It utilizes relapse prevention and
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coping skills training for substance abuse, psycho-education, and stress inoculation. PTSD
symptoms are targeted through an adaptation of cognitive strategies and coping skills for dealing
with trauma-related cues in daily life gradually including in vivo exposure. Although it also
incorporates in vivo exposure for PTSD, the treatment does not specifically focus on the
traumatic event and its memory and is therefore classified as a non-trauma-focused therapy.
SDPT was studied in a pilot RCT (Triffleman, 2000). Nineteen patients were randomly
assigned to SDPT or an active comparison group based on the twelve-step program. Both groups
showed equal reductions of PTSD severity, the number of PTSD symptoms, SUD severity and
the number of days using substances from baseline to 1 month post-treatment. Results for
treatment retention were ambiguous, showing a higher median for the SDPT group, but no group
differences for the mean number of weeks in treatment (Triffleman, 2000). A completer
definition or completer percentages could not be obtained from the article.
Based on these results, there is no evidence for a superiority of SDPT in treating
concurrent PTSD and SUD above regular SUD treatment. A methodological weakness of this
study is the small sample size. Hence, the study lacked appropriate power to detect differences
between groups (Triffleman, 2000).
Transcend. Transcend is an integrated therapy specifically designed for war-veterans
suffering from PTSD and SUD (Donovan et al., 2001). It involves a 12-week partial
hospitalization group-treatment, which is started after the completion of a substance abuse
program. Treatment goals focus on decreasing PTSD symptoms and promoting an addiction-free
lifestyle, reducing impulsive behavior and shame as well as increasing self-acceptance and self-
effectiveness. The SUD treatment is eclectic and incorporates constructivist, dynamic, CBT and
12-step orientated interventions. Although Transcend includes sharing traumatic experiences with
the group, this is not the main ingredient of the program, and it cannot be classified as imaginal
exposure (see Foa, Hembree, & Rothbaum, 2007).
Transcend was investigated in an uncontrolled study involving 46 male veterans
(Donovan et al., 2001). Results showed a significant reduction in PTSD symptoms as well as
alcohol consumption, drinking alcohol to intoxication and polysubstance drug abuse (variables
assessed from pre-treatment to 12-month follow-up) (Donovan et al., 2001). Ninety percent of the
subjects completed the full treatment program. These outcomes suggest that Transcend can be
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81
effective in treating concurrent PTSD and SUD in male veterans with high levels of treatment
retention. However, the uncontrolled research design and the relatively small number of veterans
limit the generalizability of the results.
Conclusions for non-trauma-focused treatments. The aim of this section was to give an
overview of studies investigating the effectiveness of non-trauma-focused treatments for treating
concurrent PTSD and SUD, and to evaluate whether treatments simultaneously targeting PTSD
and SUD are more effective than treatments focusing on one of the disorders alone. The non-
trauma-focused treatments investigated were SS, CBT for PTSD in SUD treatment, Transcend,
and SDPT.
SS has been investigated most extensively. The studies included in this review comprised
four uncontrolled studies, and four RCTs investigating SS. Both CBT for PTSD in SUD
treatment, and Transcend were investigated in uncontrolled studies only, and SDPT was
evaluated in a small pilot RCT.
Results of the six uncontrolled studies suggest that non-trauma-focused therapy can be
effective in treating concurrent PTSD and SUD symptoms. However, uncontrolled study designs
are limited in their generalizability in a number of ways. For instance, it remains unclear whether
results can be explained by the specific treatment strategies used or by non-specific elements of
treatment (e.g., therapist attention) or regression to the mean. Furthermore, uncontrolled studies
provide no information regarding the relative effectiveness of SS, CBT for PTSD in SUD
treatment, or Transcend compared to existing treatments. The small pilot RCT evaluating SDPT
did not provide evidence for a superiority of SDPT above regular SUD treatment. However, it
remains unclear whether these results are due to treatment characteristics or a lack of sufficient
power. Therefore, the four RCTs investigating the effectiveness of SS should be given most
weight in the evaluation of treatment results for non-trauma-focused treatments. The RCTs
confirmed the positive results regarding significant pre-post effects reported in the uncontrolled
studies, but did not show a superiority of SS above treatments for SUD only.
In conclusion, no convincing evidence was found supporting the added value of specific
non-trauma-focused therapies in the treatment of concurrent PTSD and SUD. A possible
explanation for this finding is the fact that non-trauma-focused therapies are not state-of-the-art
treatments for PTSD (Bisson et al., 2007; National Collaborating Centre for Mental Health,
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2005). As described earlier, trauma-focused treatments such as imaginal exposure or EMDR are
recommended as first-line treatments for PTSD (National Collaborating Centre for Mental
Health, 2005). We will therefore now turn to studies evaluating the effectiveness of trauma-
focused treatments for concurrent PTSD and SUD.
Trauma-Focused Therapies
Three studies could be identified investigating the effectiveness of trauma-focused
therapies for concurrent PTSD and SUD (see Tables 2 and 4). First, two integrated treatments
will be described (Concurrent Treatment of PTSD and Cocaine Dependence: Back, Dansky,
Carroll, Foa, & Brady, 2001; SS plus Exposure Therapy revised: Najavits, Schmitz, Gotthardt, &
Weiss, 2005). After that, one study will be discussed where a PTSD treatment involving imaginal
exposure is given parallel to CBT for SUD (Coffey, Stasiewicz, Hughes, & Brimo, 2006). At the
end of the section, three case studies will be discussed briefly.
Seeking Safety plus Exposure Therapy-Revised. Seeking Safety plus Exposure
Therapy-Revised is a modified version of the Seeking Safety protocol, integrating imaginal
exposure (see Foa et al., 2008) as an optional component of SS treatment. Exposure Therapy was
adapted in several ways to the specific needs of PTSD-SUD patients, e.g., patients were allowed
to process multiple traumas in one session as long as the level of affect remained high. Patients
were encouraged to process trauma memories as well as painful SUD memories. In addition, the
protocol included relapse prevention and crisis prevention strategies. The treatment consisted of
30 individual sessions in a period of 5 months.
A small uncontrolled pilot study among five male participants was carried out to explore
the effectiveness of treatment (Najavits et al., 2005). As patients could decide for themselves how
many exposure sessions they received, the relative amount of each treatment component (SS or
Exposure) could differ between subjects. The average number of sessions with exposure was
eight. Treatment results were measured pre- and post-treatment and weekly urine analysis were
carried out. Outcomes showed significant improvement for addiction severity and PTSD
symptoms. Importantly, all participants completed the total number of treatment sessions.
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83
Although these results appear promising, one should take into account the small sample
size, the lack of a control group and the lack of follow-up data after treatment when interpreting
the findings.
Concurrent Treatment of PTSD and Cocaine Dependence. The Concurrent Treatment
of PTSD and Cocaine Dependence (CTPCD) is an individual integrated treatment program for
PTSD and SUD (16 sessions; Back et al., 2001). The program has recently been modified and
renamed oncurrent treatment of PTSD and substance use disorders with prolonged exposure
(COPE) (see Back, 2010). The treatment intertwines an adapted prolonged exposure protocol
(Foa et al., 1999), involving imaginal and in vivo exposure therapy, with CBT for SUD.
Treatment effectiveness was studied in an uncontrolled study amongst 39 PTSD-SUD patients
(Brady, Dansky, Back, Foa, & Carroll, 2001). Patients received 6 to 9 sessions of imaginal
exposure, depending on individual levels of avoidance and distress. Starting with Session 6,
patients were required to additionally complete in vivo exposure assignments. Imaginal exposure
began at Session 7 for all patients. Patients who completed 10 or more sessions were defined as
completers (attending at least 3 sessions of imaginal exposure). The percentage of treatment
completers was 38.5%. For pre- to post-treatment outcome analyses, only data for the 15
treatment completers were used. Results indicated a significant decrease in self-reported and
clinician-rated PTSD symptoms until 6-months follow-up. Also, the severity in drug and alcohol
use, as well as work-related problems decreased from baseline to 6-month follow-up (ASI
subscale scores). In addition, patients reported experiencing drug-related problems on fewer days
at post-treatment in comparison to pre-treatment.
The findings reveal a significant improvement of PTSD and SUD symptoms from
baseline to follow-up. These results suggest that patients with concurrent PTSD and SUD can be
successfully treated with exposure therapy. Nevertheless, one must be cautious drawing firm
conclusions considering the lack of a control group, the relatively small sample size, the use of
completer analyses, and the high percentage of dropout (61.5%). Several randomized controlled
trials evaluating the treatment in a more rigorous way are currently underway and will provide
more conclusive evidence (see Back, 2010).
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Tab
le 4
. Stu
dies
Eva
luat
ing
Tra
uma-
focu
sed
trea
tmen
ts.
Stud
y T
reat
men
t(s)
N
umbe
r of
se
ssio
ns/
type
of
trea
tmen
t
Exp
o-
sure
D
esig
n N
Sa
mpl
e P
TSD
16
%
Mea
-su
re(s
) P
TSD
Mea
-su
re(s
) SU
D
Mea
- su
re(s
) T
imin
g
PT
SD
wit
hin
gr
oup
effe
cts
PT
SD
betw
een
grou
p
effe
cts
SUD
w
ithi
n
grou
p
effe
cts
SUD
be
twee
n gr
oup
ef
fect
s
Bra
dy e
t al.
(200
1)
A)
CT
PCD
16
/ in
divi
dual
IE
IV
U
ncon
-tr
olle
d 39
m
en a
nd
wom
en
100%
C
APS
IE
S,
MIS
S
AS
I Pr
e-po
st
/ dur
ing
trea
tmen
t 6m
onth
A +
n/
a A
+
n/a
Cof
fey
et a
l. (2
006)
A)
IE &
C
BT
for
SU
D
vers
us
B)
Rel
axat
ion
& C
BT
for
SU
D
6/ in
divi
dual
IE
RC
T
43
men
and
w
omen
10
0%
IES
A
DS
crav
ing-
V
AS
Pre-
post
/ d
urin
g tr
eatm
ent
A +
B
+/-
A
> B
A
+
B +
/-
A>
B
Dav
is e
t al.
(200
5)
A)
MC
ET
17
/ in
divi
dual
IE
IV
C
ase
stud
y 1
wom
an
100%
IE
S T
SI
M-P
TSD
-SC
Abs
ti-
nenc
e Pr
e-po
st
3mon
th
- -
- -
Naj
avits
et a
l. (2
005)
A
) SS
plu
s E
xpos
ure
The
rapy
-R
evis
ed
30
IE
Unc
on-
trol
led
5 m
en
100%
SC
ID
TH
Q
TSC
-40
WA
S
SCID
A
SI
BA
SU
Uri
ne
Pre-
post
/ du
ring
tr
eatm
ent
A+
n/
a A
+
n/a
Tue
rk e
t al.
(200
9)
A)
Exp
osur
e th
erap
y fo
r PT
SD
11/
indi
vidu
al
IE
IV
Cas
e st
udy
1 m
ale/
ve
tera
n 10
0%
SCID
PC
L
AU
DIT
Pr
e-po
st
/ du
ring
tr
eatm
ent
6mon
th
- -
- -
Vau
ghan
&
Tar
rier
(19
92)
A)
IHT
1/
indi
vidu
al
IE
Cas
e st
udy
3 m
en
100%
IE
S
Abs
ti-
nenc
e/
amou
nt o
f al
coho
l
Pre-
post
/
duri
ng
trea
tmen
t 6m
onth
- -
- -
Not
e. P
TS
D =
Pos
ttra
umat
ic s
tres
s di
sord
er. S
UD
= S
ubst
ance
use
dis
orde
r. C
TP
CD
= c
oncu
rren
t tre
atm
ent o
f P
TS
D a
nd c
ocai
ne d
epen
denc
e. I
E =
Im
agin
al e
xpos
ure.
IV
= I
n vi
vo e
xpos
ure.
CB
T =
Cog
nitiv
e be
havi
oral
trea
tmen
t. M
CE
T =
Mul
tiple
Cha
nnel
Exp
osur
e T
hera
py. I
HT
= I
mag
e H
abitu
atio
n T
rain
ing.
+ =
sig
nifi
cant
impr
ovem
ent o
f sy
mpt
oms.
- =
sig
nifi
cant
wor
seni
ng o
f sy
mpt
oms.
+/-
= n
o si
gnif
ican
t cha
nge
in s
ympt
oms.
n/a
= n
ot a
ppli
cabl
e. n
/r =
not
rep
orte
d.
16 T
he p
erce
ntag
e of
ful
l-bl
own
PT
SD in
the
rese
arch
sam
ple.
The
per
cent
age
of p
artia
l PT
SD c
an b
e de
rive
d fr
om th
e co
mpl
emen
t (10
0%).
85_Untitled-2.job85_Proefschrift Debora van Dam.job
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Add-on treatment with imaginal exposure. One study has been performed investigating
the effectiveness of adding an evidence-based treatment for PTSD to an evidence-based treatment
for single SUD. In this study imaginal exposure for PTSD was added on cognitive behavioral
treatment for SUD (Coffey et al., 2006).
The main aim of the study by Coffey et al. (2006) was to test the hypothesis that negative
emotion is a mechanism of alcohol craving. However, the study also included an RCT,
investigating the effectiveness of imaginal exposure as an add-on to regular substance abuse
treatment. In the current review, only results on the efficacy of the treatment will be presented
and discussed. Participants were randomly assigned to 6 individual sessions of imaginal exposure
(experimental treatment) or 6 individual sessions of relaxation training (active control treatment).
Both interventions were added on to a regular substance use treatment. The SUD treatment
encompassed outpatient group and individual coping skills-based therapy for SUD. Group
treatment was scheduled three times per week, whereas individual treatment was provided once
every 1 or 2 weeks. The sample consisted of 43 patients with co-morbid PTSD and SUD.
Measurements were performed at baseline, at every session of PTSD intervention, and after
completion of the 6 sessions of PTSD intervention. Imaginal exposure resulted in a significant
decrease in rated SUD craving and in self-reported PTSD symptoms for study completers,
whereas relaxation therapy did not. Study completers were defined as individuals attending all
laboratory (experimental group) or all clinical sessions (control group). Completer rates were
50% for imaginal exposure, and 63% for relaxation.
Although the sample size of this study was relatively small, results showed that imaginal
exposure could be a promising intervention when added on to an SUD program in the treatment
of concurrent PTSD and SUD. Importantly, imaginal exposure also performed better than
relaxation training as an active control treatment. However, because of the lack of follow-up data
no evidence is available on long-term effects for both treatments. A further limitation concerns
the fact that analyses were based on completer data only.
Case studies. In addition to the studies described so far, three case studies on trauma-
focused treatments for PTSD and SUD could be identified that are briefly described. Tuerk,
Brady, & Grubaugh (2009) describe the case of a male veteran diagnosed with alcohol
dependence, PTSD and traumatic brain injury. The patient received Exposure therapy for PTSD
(Foa et al., 2007), comprising imaginal and in vivo exposure, via videoconferencing. Significant
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improvements were reported for PTSD and SUD symptoms up to 6-month follow-up. Davis,
Davies, Wright, Falsetti, & Roitzsch (2005) investigated the effectiveness of Multiple Channel
Exposure Therapy (MCET) including imaginal exposure, added on regular SUD treatment (12-
step and CBT) and treatment for borderline personality disorder (Dialectical Behavior Therapy).
The female patient attended 17 individual sessions, and reported significant improvement for
PTSD and SUD complaints up to 3- month follow-up. Vaughan and Tarrier (1992) investigated
the effectiveness of one session of Image Habituation Training (IHT) for PTSD (imaginal
exposure) followed by daily homework for 2 weeks. They studied 10 different PTSD patients of
whom 3 reported comorbid substance abuse (alcohol). PTSD complaints improved greatly for
one abstinent patient. IHT was less effective for the two patients that continued drinking.
Conclusion for trauma-focused treatments. In this section, an overview was given of
studies investigating the effectiveness of trauma-focused treatments for concurrent PTSD and
SUD. The treatments were SS with Exposure Therapy-Revised, CTPCD, and imaginal exposure
as an add-on to CBT for SUD. Exposure Therapy, MCET and IHT were explored in 3 case
studies.
So far, only three studies with small sample sizes (N 43 participants) have investigated
the effectiveness of trauma-focused therapies for patients with a double diagnosis of PTSD and
SUD. All three studies suffer from a number of methodological limitations, complicating the
interpretation of their results. First, two of the three studies were uncontrolled studies, which
limits the generalizability of the results. Furthermore, for one of the studies the research sample
was very small (N = 5) (Najavits et al., 2005). In addition, the only RCT testing a trauma-focused
treatment protocol was conducted in an experimental and not a routine clinical setting (Coffey et
al., 2006). This study did not provide any data concerning the stability of treatment effects, and
analyses were only performed for completers. Other complicating factors for the interpretation
and comparison of the three studies were differences in treatment settings, and differences in the
definition of treatment completers. Finally, two of the three studies concerning trauma-focused
treatment showed high dropout rates (Brady et al., 2001; Coffey et al., 2006). Although there is
no empirical evidence indicating that trauma-focused treatment leads to an increase in substance
use, relapse, or attrition for this patient group (Back, 2010), high dropout rates might reflect
safety issues, and these should be considered carefully. On the other hand, all studies showed
improvements for PTSD symptoms as well as SUD symptoms following trauma-focused
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treatment for concurrent PTSD and SUD. The only RCT performed for trauma-focused treatment
for concurrent PTSD and SUD reported superior effectiveness of trauma-focused treatment
(imaginal exposure) added on SUD treatment above an active control treatment (relaxation)
added on SUD treatment.
So far, there is not enough proof available supporting the use of trauma-focused treatment
for those with a comorbid diagnosis for PTSD and SUD. Nonetheless, the preliminary results
presented earlier hold promise that patients may profit substantially from trauma-focused
treatment, if they are able to tolerate exposure-based interventions and complete their treatment.
This is in line with data from research into PTSD without SUD (Bisson et al., 2007).
Conclusions
The purpose of this review was to give an overview of psychological treatments for
concurrent PTSD and SUD. In addition, it was aimed to evaluate whether these treatments are
superior to treatments focusing on one of the disorders alone. Hereby a distinction was made
between trauma-focused versus non-trauma-focused treatments.
In total, seventeen studies were identified evaluating ten treatment protocols (Table 2).
Four treatments were non-trauma-focused (SS; CBT for PTSD added on SUD treatment; SDPT;
Transcend), and six treatments were trauma-focused (SS plus Exposure Therapy-Revised;
CTPCD; imaginal exposure added on SUD treatment; Exposure Therapy, MCET; IHT). This
review discussed six RCTs, eight uncontrolled studies, and three case studies. Ten studies
showed significant reductions in PTSD and SUD symptoms for the experimental treatments. Two
studies found significant symptom-improvements for PTSD, but not for SUD (Cook et al., 2006;
Hien et al., 2009). One study reported symptom improvements for the sample as a whole, and did
not specify results for the experimental treatment alone (Triffleman, 2000), and one study only
investigated symptom changes on an individual level (Norman et al., 2010). Three studies did not
perform follow-up measurements (Coffey et al., 2006; Cook et al., 2006; Najavits et al., 2005).
However, the studies comprising follow-up measurements generally showed that effects
remained stable at follow-up.
The five RCTs investigating the relative effectiveness of non-trauma-focused therapies
compared to single SUD treatment included SS, and SDPT (Hien et al., 2004; Hien et al., 2009;
Najavits et al., 2006; Triffleman et al., 1999; Zlotnick et al., 2009). None of these studies
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provided evidence that these non-trauma-focused therapies are more effective in treating
concurrent PTSD and SUD than interventions focusing on one of the disorders alone. Only one
RCT evaluated the relative effectiveness of trauma-focused therapy (Coffey et al., 2006).
Although results are preliminary, the completer analysis from this trial shows a significantly
higher effect for the trauma-focused intervention than a control condition providing relaxation
training. Based on these preliminary findings as well as results from the literature on treatments
for PTSD without SUD (Bisson et al., 2007), it appears promising to investigate the efficacy of
trauma-focused treatment for comorbid PTSD and SUD using more rigorous methodology.
The current review is limited by its purely qualitative nature. We were therefore not able
to compare the different treatment approaches in a quantitative way. In the future, meta-analytic
procedures should be used to this end. However, a larger number of studies using sound
methodology are needed before a meta-analysis in this area appears warranted. In the following,
we will discuss a number of methodological limitations of and inconsistencies between the
existing studies before turning to recommendations for future research. First, the studies
presented a large variety in research samples and settings (veterans, women, prisoners), which
makes it difficult to directly compare treatment results. Second, there was a large variability
regarding the way, in which the key dependent variables were operationalized. For example, not
all studies used the same type of outcome measures for PTSD and SUD. In addition, there was a
huge variation in the definition of treatment completers, varying from 25% to 100% attendance.
Therefore, a comparison of dropout across studies does not appear to be very meaningful.
Furthermore, the type and timing of follow-up measurements differed considerably, which again
complicates a comparison across studies. Third, the interpretation of the results is seriously
complicated by the relatively small amount of RCTs conducted so far (N = 6). In addition, these
RCTs differ regarding the control groups included. For example, different kinds of SUD-TAU
programs were used as comparison groups. Finally, the pilot RCT investigating SPDT comprised
such a small research sample that it lacked the necessary power (Triffleman, 2000), and therefore
it cannot be considered as a rigorous study.
Based on the review of the literature, the following recommendations can be made for
future research. First, research directly comparing trauma-focused versus non-trauma-focused
interventions is needed in order to be able to draw conclusions regarding their relative
effectiveness for patients with concurrent PTSD and SUD. Preliminary evidence regarding the
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effectiveness of imaginal exposure plus SUD treatment, such as implemented in the COPE
treatment approach, appears promising. Though, more rigorous research evaluating the efficacy
of these treatments in necessary. Importantly, given the high dropout rates reported in studies
conducted so far, future research need to pay close attention to safety issues and retention of
patients in treatment. Reassuringly, several RCTs investigating trauma-focused treatment for
comorbid PTSD and SUD appear to be currently underway (Back, 2010). Additionally, it appears
interesting to investigate the effectiveness of other types of trauma-focused interventions as part
of combined treatments for concurrent PTSD and SUD. An apparent gap is the lack of studies
investigating the effectiveness of EMDR in this area. In addition, cognitive processing therapy
(CPT) (Resick & Schnicke, 1992), a widely used evidence-based treatment for PTSD has to our
knowledge not been evaluated for patients with comorbid PTSD and SUD, yet. CPT focuses on
deconstructing dysfunctional conflicting assumptions and beliefs about the world and the self.
Trauma-related exposure is provided by letting patients write in detail about the most traumatic
incident(s), followed by reading it to themselves and to the therapist. Writing assignments are
also used in Structured Writing Therapy (SWT) for PTSD, which has been found to result in
sharply reduced levels of intrusion and avoidance, depression, anxiety and somatization (Lange et
al., 2003). Importantly, CPT and SWT appear equally effective to CBT involving standard
imaginal exposure to the trauma (Resick, Nishith, Weaver, Astin, & Feuer, 2002; Van Emmerik,
Schoorl, Emmelkamp, & Kamphuis, 2006).
In future research more attention should be paid to the methodology of studies in this
area. First of all, there is a strong need for rigorous study designs, where patients are randomly
allocated to treatment conditions. Secondly, the use of long-term follow-up measurements is very
important to investigate the sustainability of treatment results over a longer period of time.
Moreover, we recommend the development of general guidelines for studies investigating the
effectiveness of concurrent treatment for PTSD and SUD. By this means, an identical timing of
follow-up measurements, and measurements of constructs can be established across different
studies. Also, inclusion criteria, and outcome measures can be equally defined, as well as clear
and identical definitions for dropout, and retention. The establishment of general guidelines
would serve to compare the results of different studies in a meta-analysis, and would enable us to
take this area of research to a next level.
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CChapter 5
The effectiveness of integrated trauma-focused treatment
for concurrent posttraumatic stress disorder and
substance use disorder: a randomized controlled trial
Van Dam, D., Vedel, E., Ehring, T., & Emmelkamp, P. M. G. (submitted). The effectiveness of Integrated Trauma-
focused Treatment for Concurrent Posttraumatic Stress Disorder and Substance Use Disorder: A Randomized
Controlled Trial
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Abstract
The aim of this study was to investigate the effectiveness of an integrated treatment for
concurrent posttraumatic stress disorder (PTSD) and substance use disorder (SUD) that is based
on Structured Writing Therapy for PTSD (SWT) and cognitive behavioral treatment for SUD
(CBT/SUD). A randomized controlled trial was performed within a substance abuse treatment
center, comparing CBT/SUD + SWT (N = 53) with CBT for SUD treatment (CBT/SUD) alone
(N = 43). Outcome measures included the Posttraumatic Diagnostic Scale (PDS), the Timeline
Follow Back for alcohol and drugs (TLFB), and the Structured Clinical Interview for DSM-IV
axis I Disorders (SCID-I). Assessments took place at pre-treatment, and mid-treatment, directly
after treatment, and 3 months post-treatment. Intent to treat (ITT) and completer analyses were
performed. Treatment effectiveness was investigated using a linear mixed model (LMM) and
multiple imputation (MI). Both treatments had a positive effect on PTSD and SUD symptoms for
ITT as well as completer analyses. In addition, completer analyses favored CBT/SUD + SWT
above CBT/SUD in reducing PTSD symptoms. The findings are encouraging, since they present
evidence that trauma-focused treatment for concurrent PTSD and SUD may be superior to
treatment for SUD alone, under the condition that the received treatment dosage is sufficient.
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Introduction
Approximately 30% of the substance use disorder (SUD) patients are formally diagnosed
with posttraumatic stress disorder (PTSD) (Harrington & Newman, 2007; Kimerling, Trafton, &
Nguyen, 2006). Compared to patients with SUD alone, patients with concurrent PTSD and SUD
show higher levels of psychopathology, poorer physical health, and more problems in social
relationships (Najavits, Weiss, & Shaw, 1999). Several studies have investigated the effects of
SUD treatment for this patient group. There are indications that SUD treatment is beneficial for
patients with concurrent PTSD and SUD, and that SUD treatment leads to improvements for both
PTSD and SUD symptoms (Brown, 2000; Ouimette, Brown, & Najavits, 1998; Van Dam, Vedel,
Ehring, & Emmelkamp, 2012). However, clinical complications are also associated with this
patient group. Some studies suggest that SUD outcomes are worse for patients with concurrent
PTSD and SUD, compared with those for patients with SUD only, especially in the long term
(Ouimette et al., 1998), although these findings have not been consistently replicated (Norman,
Tate, Anderson, & Brown, 2007). Clinical studies investigating the patterns in substance use
relapse for patients with concurrent PTSD and SUD, have repeatedly shown a positive
association between PTSD symptoms and relapse (Back, Brady, Sonne, & Verduin, 2006;
Norman et al., 2007; Read, Brown, & Kahler, 2004). Also, cognitive experimental research has
revealed an increase of craving, after the exposure to personalized trauma-image cues (Coffey et
al., 2002; Saladin et al., 2003). This suggests that comorbid PTSD symptoms may increase the
risk for relapse in substance use. Consequently, a decrease of PTSD symptoms may improve
SUD treatment outcomes for patients with concurrent PTSD and SUD. Therefore these patients
may benefit from PTSD interventions during SUD treatment. This rationale has become more
generally accepted in the recent years (Bradizza, Stasiewicz, & Paas, 2006; Najavits et al., 2007).
However, in clinical practice the traditional sequential treatment approach is still common, where
patients are treated for SUD first, and are not referred to PTSD treatment until they have
completed SUD treatment successfully (Henslee & Coffey, 2010; McGovern et al., 2009).
In the last decade, several psychological treatments for concurrent PTSD and SUD have
been developed and evaluated. These treatments can be divided into trauma-focused and non-
trauma-focused treatments (Van Dam et al., 2012). Specifically, trauma-focused PTSD treatment
focuses on the modification of the memory of the traumatic event and trauma-related appraisals,
e.g. by using imaginal exposure to reprocess the traumatic event (National Collaborating Centre
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for Mental Health, 2005; Powers, Halpern, Ferenschak, Gillihan, & Foa, 2010). Non-trauma-
focused treatment provides patients with coping skills to manage their trauma symptoms and to
improve functioning but do not include strategies aimed at processing the trauma memory
(Donovan, Padin-Rivera, & Kowaliw, 2001; McGovern et al., 2009; Najavits et al., 2003;
Triffleman, Carroll, & Kellogg, 1999). Until recently, most treatments for concurrent PTSD and
SUD that have been described in the literature were non-trauma-focused. This may be due to the
concern that trauma-focused exposure could lead to symptom exacerbation, dropout, and adverse
events for patients with concurrent PTSD and SUD (Hien, Cohen, Miele, Litt, & Capstick, 2004;
Najavits, 2004; Pitman et al., 1991).
In past studies investigating combined treatments for comorbid SUD and PTSD, non-
trauma-focused treatments did not outperform active control conditions, such as regular SUD
treatment (Boden et al., 2012; McHugo & Fallot, 2011; Van Dam et al., 2012). This questions the
added value of non-trauma-focused interventions for this group of patients, especially since there
is limited evidence for non-trauma-focused treatments in single diagnosis PTSD (Bisson et al.,
2007). The clinical guidelines for single diagnosis PTSD advise not to offer non-trauma-focused
treatment in routine clinical practice, and recommend trauma-focused treatment, such as
prolonged imaginal exposure or EMDR, as first-line treatments for PTSD (Bisson et al., 2007;
National Collaborating Centre for Mental Health, 2005). The positive findings for single
diagnosis PTSD seem to justify effectiveness studies for trauma-focused treatment among
patients with concurrent PTSD and SUD. Moreover, it appears that exposure-based interventions
are not necessarily associated with an increase in attrition or relapse to drugs or alcohol (Brady,
Dansky, Back, Foa, & Carroll, 2001).
At the time of conceiving the current study, four RCTs had been published investigating
combined treatment for PTSD and SUD (Coffey, Stasiewicz, Hughes, & Brimo, 2006; Cohen &
Hien, 2006; Hien et al., 2004; Najavits, Gallop, & Weiss, 2006; Triffleman, 2000), and only one
had investigated the efficacy of trauma-focused treatment (Coffey et al., 2006). Outcomes of this
study, partly performed in a laboratory setting, suggested that a trauma-focused intervention is
superior in reducing symptoms of PTSD compared with treatment as usual (TAU) (Coffey et al.,
2006). Recently, an RCT has been published investigating concurrent treatment of PTSD and
SUD using prolonged exposure (COPE) (Mills et al., 2012). This study has been performed
within routine clinical care. Outcomes provided preliminary evidence that a trauma-focused
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intervention is superior in reducing symptoms of PTSD compared with TAU (Mills et al., 2012).
Though, the SUD intervention in this study was not standardized across study participants, which
complicates the interpretation of study results. In general, integrated trauma-focused treatments
are promising, but evidence is still limited, and only one RCT had been performed in routine
clinical care (Mills et al., 2012).
The current study builds on this earlier research of trauma-focused interventions for
patients with concurrent PTSD and SUD and aims to extend it in several ways. The purpose was
to investigate the effectiveness of an integrated trauma-focused treatment for concurrent PTSD
and SUD in a routine clinical setting with SUD therapists with time-limited training in PTSD
treatment. Every day practice was mirrored as much as possible, in order to enlarge the
generalizabilty of our results to clinical practice. The intervention for SUD was standardized in
both conditions to narrow down the specific effect of the concurrent treatment more specifically.
The intervention for SUD consisted of cognitive behavioral treatment (CBT) for SUD
(CBT/SUD). This is an evidence-based intervention comprising coping skills training and relapse
prevention strategies (Emmelkamp & Vedel, 2006). The interventions focus on recognizing and
coping with high-risk situations that precipitate substance use, and on providing patients with
new strategies and skills through modeling, behavioral practice and homework assignments
(Monti, Kadden, Rohsenow, Cooney, & Abrams, 2002). They stimulate the use of self-control
/her substance use (Carroll, 1998;
Monti et al., 2002). The intervention for PTSD was Structured Writing Therapy (SWT) (Van
Emmerik, Kamphuis, & Emmelkamp, 2008). SWT uses writing assignments to process the
traumatic memory. There were several grounds for choosing SWT as an intervention for this
study. First, we assumed that patients would feel more in control with SWT than with standard
trauma-focused exposure. After careful instructions, patients could decide for themselves on what
time and what place they carried out the trauma-focused exposure. We presumed that the feeling
of control would make the trauma-focused exposure ,
and would decrease the chance of dropout within this vulnerable patient group. In addition, SWT
has shown similar benefits as standard imaginal trauma exposure treatment in earlier research
(Van Emmerik, Schoorl, Emmelkamp, & Kamphuis, 2006), implying that it has the same efficacy
as the PTSD gold standard treatment (Bisson et al., 2007). In addition to trauma-focused
exposure, SWT also encourages cognitive reappraisal of trauma-related thoughts and social
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sharing of the traumatic event. Results from several studies support the effectiveness of SWT in
the treatment of PTSD (Lange et al., 2003; Lange, Van de Ven, Schrieken, & Emmelkamp, 2001;
Van Emmerik et al., 2008), and SWT has been found to result in sharply reduced levels of
intrusion and avoidance, depression, anxiety and somatization (Lange et al., 2003).
The aim of the present randomized controlled trial (RCT) was to investigate the
effectiveness of the integrated treatment protocols of CBT for SUD and SWT (CBT/SUD +
SWT) in treating concurrent PTSD and SUD, compared with CBT/SUD. Based on the research
findings discussed earlier, it was expected that (1) both treatments would be effective in
decreasing symptoms of SUD and PTSD, (2) CBT/SUD + SWT would be significantly more
effective than CBT/SUD in reducing symptoms of PTSD, and (3) CBT/SUD + SWT would be
significantly more effective than CBT/SUD in reducing symptoms of SUD.
Method
Participants
Participants were outpatients of the Jellinek, a large substance abuse treatment center in
Amsterdam, The Netherlands. Recruitment took place between July 2008 and July 2011.
Inclusion criteria were: a diagnosis of substance abuse or substance dependence according to the
Diagnostic and Statistical Manual (DSM-IV; American Psychiatric Association [APA], 1994),
and a diagnosis of PTSD according to DSM-IV or partial PTSD. Following Blanchard, Hickling,
Taylor, Loos, & Gerardi (1994), partial PTSD was defined as (1) meeting symptom criteria for
the reexperiencing cluster, (2) meeting criteria for either the avoidance/numbing cluster or the
hyperarousal cluster, and (3) meeting DSM-IV PTSD criteria E (duration) and F (impairment).
One of the reasons to include partial PTSD patients was that patients were diagnosed during the
intake phase, while still using substances. The aim of including this group was to prevent missing
patients who were suppressing C or D cluster symptoms with alcohol and/or drugs. Former
studies have shown a link between those clusters and substance use (Najavits et al., 2003;
Saladin, Brady, Dansky, & Kilpatrick, 1995; Shipherd, 2005; Stewart, Conrod, Pihl, & Dongier,
1999). In addition, partial PTSD patients have been shown to report comparable levels of clinical
distress and disability to patients with PTSD (Norman, Stein, & Davidson, 2007). Therefore,
including this group in the study appeared clinically informative, and ethically sound. Other
inclusion criteria were being allocated to outpatient treatment, being 18 years or older, and
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sufficient understanding of the Dutch or English language. Nearly all patients could follow the
test did not reveal
between-group differences for the number of Dutch speaking patients (p = .63), and no different
study outcomes were found when English speaking patients were eliminated from the analyses.
Exclusion criteria were nicotine dependency as the only SUD, severe (psychiatric)
problems that required immediate clinical care (e.g., psychotic symptoms, manic episode, current
suicidal ideation, domestic violence), severe cognitive disorders, a current diagnosis for
borderline personality disorder (BPD), or receiving concurrent psychotherapy for any kind of
psychological disorder. Patients with severe problems or disorders were excluded for ethical
reasons as their situation demanded specific care or immediate crisis interventions that could not
be offered in the setting of a research trial.
BPD patients were excluded preventively, as this disorder is characterized by emotional
instability and a tendency to crisis behavior. Also, BPD patients needed a more intensive
treatment than the outpatient treatments offered in this study. Participants were not allowed to
have alternative psychological care during the time from pre-treatment up to follow-up to
standardize the offered treatments, which was important to investigate the specific effect of the
experimental treatment SWT.
Figure 1 shows the participant flow from a positive PTSD screen to the 3-month follow-
up. A total of 99 patients met study criteria and were randomized into the study. Three
participants decided to withdraw their participation in the study before they started treatment. The
final sample consisted of 96 participants. A summary of sample characteristics and between
group analyses are found in Tables 1 and 2. The overall sample consisted of 55 males and 41
females, with a mean age of 41 (SD = 10.3).
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Figure 1. CONSORT flowchart of the recruitment and retention of participants. t1 = baseline, t2 = mid-treatment, t3 = post-treatment; t4 = 3-month follow-up, ITT= intention-to-treat.
141 eligible
43 in ITT analyses 53 in ITT analyses
41 completed t2 (mid-treatment) 41 completed t3 (post-treatment) 36 completed t4 (3 mo follow-up)
30 completed t2 (mid-treatment) 31 completed t3 (post-treatment) 30 completed t4 (3 mo follow-up)
53 SWT + CBT/SUD 27 (2 of these dropouts continued treatment in inpatient setting)
43 CBT/SUD 17 % sessions) (1 of these dropouts continued treatment in inpatient setting)
96
3 withdrew from study after randomization.
99 randomly allocated
99 t1 (pre-treatment)
42 declined (did not want to participate)
367 ineligible 205 no (subthreshold) PTSD
42 allocated to inpatient treatment 44 severe (psychiatric) problems 23 concurrent psychotherapy 23 borderline personality disorder 4 severe cognitive problems 5 language
17 other 4 unknown
508 positive PTSD screens
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Table 1. Sample Characteristics: Demographic Variables.
Demographics
Overall
(N = 96)
CBT/SUD + SWT
(N = 53)
CBT/SUD
(N = 43)
Between group
Analyses
Mean age (SD) 41.0 (10.3) 40.8 (10.6) 41.4 (11.2) t (95) = 0.71, p = .48
Gender, n (%)
Male 55 (55.2) 29 (54.7) 26 (60.5) p = .57
Female 41 (44.8) 24 (45.3) 17 (39.5)
Ethnicity, n (%)
Dutch 62 (64.6) 36 (67.9) 26 (60.5) p = .86
European (other) 10 (10.4) 6 (11.3) 4 (9.3)
Arabic/ Moroccan/ Turkish 8 (8.3) 4 (7.5) 4 (9.3)
Black/ Surinamese/ Caribbean 12 (12.5) 5 (9.4) 7 (16.3)
Other 4 (4.2) 2 (3.8) 2 (4.7)
Education (certificate), n (%)
No education, primary school 7 (7.3) 4 (7.5) 3 (7.0) p = .58
Secondary school, lower level17 17 (17.7) 8 (15.1) 9 (20.9)
Secondary school, higher levela 41 (42.7) 23 (43.4) 18 (41.9)
Postsecondarya 19 (19.8) 9 (17.0) 10 (23.3)
Missing 12 (12.5) 9 (17.0) 3 (7.0)
Relationship status, n (%)
Single 69 (71.9) 34 (64.2) 35 (81.4) p = .06
Partner 27 (28.1) 19 (35.8) 8 (18.6)
Source of income, n (%)
No work 46 (47.9) 24 (45.3) 22 (51.2) p = .27
Work 47 (49.0) 26 (49.1) 21 (48.8)
Missing 3 (3.1) 3 (5.7) 0 (0)
Treatment attendance
Completers (>75%), n (%) 52 (54.2) 26 (49.1) 26 (60.5) p = .27
Mean number of sessions (SD )
Total group - 11 (5.6) 7 (3.7)
Note. CBT/SUD + SWT = Cognitive behavioral treatment for substance use disorder plus Structured Writing Therapy. CBT/SUD = Cognitive behavioral treatment for substance use disorder. Level of education: secondary school, lower level = VBO/LBO/MAVO/Avo; secondary school, higher level = HAVO, VWO, MBO; postsecondary = HBO, university, doctor of philosophy.
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Table 2. Sample Characteristics: Diagnostic Status (Current).
Diagnostic status Overall
(n =96)
CBT/SUD +
SWT (n =53)
CBT/SUD
(n =43)
Analyses
PTSD diagnosis (full-blown), n (%) 62 (64.6) 34 (64.2) 28 (65.1) p = 1.0
Primary SUD diagnosis, n (%)18
Alcohol 51 (53.1) 29 (54.7) 22 (51.2) p = .83
Drugs
Cannabis 26 (27.1) 14 (26.4) 12 (27.9) p = 1.0
Cocaine 10 (10.4) 7 (13.2) 3 (7.0) p = .50
Other 5 (5.2) 2 (3.8) 3 (7.0) p = .65
Substance Dependence 87 (90.6) 49 (92.5) 38 (88.4) p = .51
Substance Abuse 5 (5.2) 3 (5.7) 2 (4.7) p = 1.0
Other ax-I diagnoses, n (%)
Depressive disorder 18 (18.8) 8 (15.1) 10 (23.3) p = .43
Panic disorder 4 (4.2) 3 (5.7) 1 (2.3) p = .40
Panic disorder with agoraphobia 2 (2.1) 2 (3.8) 0 (0) p = .50
Social Phobia 9 (9.5) 3 (5.7) 6 (14.3) p = .18
Specific phobia 8 (8.4) 5 (9.4) 3 (7.1) p = 1.0
Obsessive compulsive disorder 1 (1.0) 1 (1.9) 0 (0) p = 1.0
General anxiety disorder 2 (2.1) 1 (1.9) 1 (2.3) p = 1.0
Eating disorder 3 (3.1) 2 (3.8) 1 (2.3) p = 1.0
Note. PDS = Posttraumatic Diagnostic Scale. PTSD = Posttraumatic stress disorder. SUD = Substance use disorder. CBT/SUD + SWT = Cognitive behavioral treatment for substance use disorder plus Structured Writing Therapy. CBT/SUD = Cognitive behavioral treatment for substance use disorder.
Sixty-two patients met criteria for PTSD, and 34 met criteria for partial PTSD. There were no
significant differences between the CBT/SUD + SWT and the CBT/SUD group for sample
characteristics, baseline measures, dropout, or diagnostic status.
18 SUD diagnoses were completely in remission during the last month for N = 4 patients.
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Treatments
Cognitive behavioral treatment for SUD (CBT/SUD). CBT/SUD was based on a
manual (De Wildt, 2000) and consisted of 10 individual sessions of 45 minutes. This
intervention, using this specific manual and format, is treatment-as-usual (TAU). This is not only
the case in the clinical setting of this study, but also in most other substance abuse treatment
centers in the Netherlands. The sessions were extended over a 15 weeks period. The first six
sessions were offered weekly. CBT/SUD can be described as a coping skills training
(Emmelkamp & Vedel, 2006). The treatment rationale is that SUD results from inadequate efforts
to deal with stressors in daily life. It focuses on recognizing situations that precipitate substance
abuse, and on overcoming skill deficits. In addition, attention is paid to handling craving, and
practicing social skills to deal with social pressure to use substances. Homework assignments are
important treatment tools. An extensive description of coping skills training is given by
Emmelkamp and Vedel (2006). Whereas the content of the first seven sessions was defined by
the manual, therapists and patients could choose from a selection of manualized interventions for
the last three sessions. Possible modules included a repetition of topics addressed in earlier
sessions as well as new topics (e.g., social skills, problem solving skills, and dealing with
negative emotions).
Cognitive behavioral treatment for SUD plus Structured Writing Therapy
(CBT/SUD + SWT). CBT/SUD + SWT comprised a combination of CBT/SUD and SWT for
PTSD and was based on a manual. The treatment consisted of 15 weekly individual sessions of
60 minutes. The first five sessions covered a condensed version of the CBT/SUD treatment
described above. In Session 6, SWT was introduced. SWT consisted of eight sessions subdivided
into three phases. -
trauma-focused exposure. Patients were guided to write in detail about the most traumatic
event(s) they had experienced. The writing had to be in the first person and in the present tense,
addressing sensory experiences, painful facts, and thoughts and emotions experienced during the
consequences, and on changing dysfunctional appraisals related to the event. Patients were
guided to write an advice letter to an (imaginary) friend or loved one who had experienced the
same event. Patients were asked to give advice to this person how they could best deal with
thoughts, emotions and consequences related to the trauma. In a second step, the patient was
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instructed to write a similar letter to him- ing and
sharing ritual consisted of writing a final letter, where the patient reflected on the trauma, its
impact on his/ her life, and his/ her resolutions for dealing with the trauma in the future. During
the whole treatment, writing assignments were introduced and discussed during the treatment
sessions. If patients could not find a quiet or safe place at home to fulfill their writing
assignments, they could write the assignments at the Jellinek treatment center. CBT/SUD + SWT
also incorporated two flexible sessions. Patients and therapists could decide whether they wanted
to repeat an earlier topic, or whether they wanted to use one of the additional CBT/SUD modules
described above. If necessary, it was possible to use the flexible sessions in advance to prolong
the self-confrontation or the cognitive reappraisal phase.
Because substance use could interfere with the extinction of trauma (Stewart & Conrod,
2003), it was required to achieve abstinence before Session 6, and to maintain abstinence for the
rest of the treatment in both treatment conditions. A routine Jellinek treatment protocol was used
to allocate patients to a detoxification program (one week inpatient program) previous to
treatment or during treatment (before the sixth session). No group differences were found for the
number of patients allocated to a detoxification program (CBT/SUD + SWT; N = 7; CBT/SUD;
N N = 96) = 0.01, p = .92.
In order to prepare patients with concurrent PTSD and SUD for possible difficulties
during detoxification and SUD treatment, psycho-education about PSTD and SUD was provided
in the first treatment session (Ford, Russo, & Mallon, 2007; Stewart & Conrod, 2003; Van Dam
et al., 2012). For ethical reasons, psycho-education was not only added to CBT/SUD + SWT, but
also to the CBT/SUD protocol.
Therapists
All therapists were regular therapists of the Jellinek with a mas
psychology and formal training in cognitive behavioral therapy. All therapists had thorough
experience in delivering CBT/SUD interventions. Therapists were trained to carry out the
CBT/SUD + SWT intervention according to an extensive manual by the first and last author
before they participated in the study. Therapists received the training in one session, individually
or together with another therapist. The duration of the training sessions was approximately two
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110
hours. Therapists were supervised in weekly sessions by the last author. Treatment adherence was
monitored carefully during supervision. All therapists delivered both CBT/SUD + SWT and
CBT/SUD interventions.
Measures
The outcome measures for PTSD were change in the severity of PTSD symptoms, and
PTSD diagnostic status. The outcome measures for SUD were change in substance use, and
fulfillment of the diagnostic criteria of SUD.
The Posttraumatic Diagnostic Scale (PDS) (Foa, Cashman, Jaycox, & Perry, 1997) was
used as a primary outcome measure for PTSD. The questionnaire consists of 17 items
corresponding to the DSM-IV criteria for PTSD, that are rated on a 4-point Likert-scale (0 = not at
all or only one time; 3 = five or more times a week/ almost always), and 9 items assessing
impairment in different life areas. PTSD symptom severity scores are obtained by summing the
17 symptom items, with higher scores indicating greater symptomatology (Foa et al., 1997). The
PDS has shown good reliability and validity in the past (Foa et al., 1997; Sheeran & Zimmerman,
2002), including high sensitivity and specificity (Ehring, Kleim, Clark, Foa, & Ehlers, 2007).
With the Timeline Follow Back (TLFB) (Sobell & Sobell, 1996), retrospective estimates
of daily use of alcohol and drugs were obtained for a time frame of 90 days. Its psychometric
characteristics for alcohol use have been extensively evaluated (Fals-
McFarlin, & Rutigliano, 2000; Vakili, Sobell, Sobell, Simco, & Agrawal, 2008). There is also a
high degree of agreement between client self-report and official records such as days in jail or
treatment facilities (Dawe, Loxton, Hides, Kavanagh, & Mattick, 2002).
our study.
DSM-IV axis I disorders, including SUD and PTSD, were assessed with the Dutch version
of the Structured Clinical Interview for DSM-IV axis I Disorders (SCID-I) (First, Spitzer,
Gibbon, & Williams, 1996; Van Groenestijn, Akkerhuis, Kupka, Schneider, & Nolen, 1999). The
Dutch version of SCID-I has shown a fair interrater agreement for the SUD module (kappa=
0.65), and an excellent interrater agreement for the PTSD module (kappa= 0.77) (Lobbestael,
Leurgans, & Arntz, 2010).
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The Jellinek-PTSD screening questionnaire (J-PTSD) was used to screen for (partial)
PTSD (Van Dam, Ehring, Vedel, & Emmelkamp, 2013a). The J-PTSD was specifically
developed to screen for PTSD within the group of SUD patients. This screener has shown high
sensitivity (.87), specificity (.75), and overall efficiency (.77) in detecting PTSD among SUD
patients when using a cutoff score of 2 (Van Dam et al., 2013a). for the J-PTSD in
our study was .87.
The McLean screening instrument for borderline personality disorder (MSI-BPD)
(Zanarini et al., 2003) was used to screen for borderline personality disorder (BPD). Good
sensitivity (.81) and specificity (.85) were found for a cutoff score of 7 (Zanarini et al., 2003).
Patients with a score of
Borderline personality disorder was assessed with the Dutch version of the Structured
Clinical Interview for DSM-IV axis II Disorders (Weertman, Arntz, & Kerkhofs, 2000). The
Dutch version of SCID-II has shown an excellent interrater agreement for the BPD module
(kappa= 0.91) (Lobbestael et al., 2010).
Procedures
All patients attending an intake interview were screened for PTSD using the Jellinek-
PTSD. Subjects with a positive screen were invited for further assessment to determine
diagnostic status. Eligible patients with a formal diagnosis for partial PTSD or PTSD received
information about the study (face-to-face and in writing). Then another appointment was made to
obtain written informed consent, and to conduct the pre-treatment assessment (t1). After pre-
treatment assessment, patients were randomly assigned to either CBT/SUD + SWT or CBT/SUD
by asking them to draw one out of two closed envelopes. Each patient was approached for an
additional three assessments during the study: mid-treatment (t2) (after the fifth session), post-
treatment (t3), and 3 months post-treatment (t4). Patients were invited to the Jellinek treatment
center for all assessments, with the exception of the shorter 3-month follow-up. This follow-up
was collected by telephone. Mid-treatment or post-treatment assessments were also collected by
telephone if patients were unable or unwilling to participate in a face-to-face assessment at the
treatment center. Assessment by telephone was carried out for N = 3 patients at mid-treatment,
and for N = 14 patients at post-treatment. There was no financial compensation for research and
treatment participation.
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The study was approved by the local ethics committee, and submitted to the Clinical
Trials Register, ClinicalTrials.gov (Trial # NCT00763542).
Statistical Methods
All analyses were performed using the IBM Statistical Package for Social Science
(SPSS), version 19.0 for Windows. T tests and ² tests were used to compare
the CBT/SUD + SWT to the CBT/SUD group on demographic characteristics. For the analysis of
treatment effects, intent to treat (ITT) analyses and completer analyses were performed.
Completer analyses included all patients who completed at least 75% of the therapy sessions.
Missing data patterns were identified and classified as item non-response and unit non-
response (De Leeuw, Hox, & Huisman, 2003). The loss of cases due to item non-response was
very small for each questionnaire (< 2%). Therefore item-non response was handled with the
SPSS syntax of response function imputation for item-non response (Van Ginkel, Van der Ark, &
Sijtsma, 2007). In the case of unit non-response, a complete questionnaire is missing. It is
important to note that in the current study, unit non-response does not equal treatment dropout.
Patients who did not complete 75% of their treatment sessions could still participate in study
measurements (and vice versa).
Statistical treatment effectiveness was investigated using a linear mixed model (LMM) 19
with random intercept and slope, using the maximum likelihood algorithm (ML). As there were
no patterns in missing data apparent, we assumed that data were missing at random (MAR)
(Molenberghs et al., 2004). Treatment condition was used as a factor, and time as a covariate.
Dependent variables were the PDS total score and the TLFB (days of abstinence). For both the
PDS and the TLFB, a main effect for time was expected as well as an interaction effect for
condition and time. To investigate which covariance structures fitted our data optimally, each
LMM analysi iterion (AIC) as
an indicator of model fit. Models with the smallest AIC were chosen for the final analyses. Effect
sizes and confidence intervals for LMM were calculated using the estimated means (Feingold,
19 Missing data analyses like MI or ML methods appear to be appropriate methods for small sample sizes (N = 50) (Graham, 2009).
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2009; Hedges & Olkin, 1985)20. In case of skewed distributions additional analyses were
performed after logtransformation.
LMM cannot be used if outcomes are measured less than three times, and in the current
study diagnostic status was only measured at pre- and post-treatment. Therefore, multiple
imputation (MI) (m= 40) was performed in these cases (Graham, 2009). Whole scales were
imputed using the complete datafile (k= 107) (Graham, 2009). Non-
exact test, tests and McNemars were performed on the imputed dataset to examine within
(from pre- to post-treatment) and between group differences (post-treatment) for diagnostic
status. The changes in diagnostic status were considered informative in evaluating clinically
significant change. The imputed dataset was also used to investigate clinically reliable change
(Jacobson & Truax, 1991). The reliable change index (RCI) was calculated to
investigate whether change was not merely due to fluctuations of the PDS or the TLFB (Evans,
Margison, & Barkham, 1998; Jacobson & Truax, 1991)21.
Results
Treatment Attendance
Patients were classified as treatment completers if they had attended more than 75% of the
sessions (12 sessions or more for the CBT/SUD + SWT condition, and 8 sessions or more for the
CBT/SUD condition). Overall, fifty-two (54%) patients completed the treatment. No significant
differences were found for completer percentages between the two treatment groups, ² (1, N =
96) = 1.25, p = .27 (see Table 3). Reported reasons for dropout were decreased motivation for
treatment (55%), troubles in other areas of life (work, relationship, housing) (16%), admittance to
penitentiary facility (5%), severe physical illness (5%), symptom improvement (7%), and other
(12%). No differences between both treatment groups were revealed on these variables ² (5, N =
96) = 2.50, p = .78.
Effect of Treatment on PTSD
20 The difference between the estimated means of the two groups at end of study (determined from the coefficient for the slope difference and length of study) divided by the baseline standard deviation: dgma- SDraw. 21 RC = x2 xl SEdiff = SD1 2 1-r SEdiff
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Descriptive data for PTSD outcome measures are displayed in Tables 3 and 4. These
outcome measures were PTSD symptom severity (PDS) and PTSD diagnostic status (SCID
diagnosis).
PTSD symptom severity. In the ITT sample, a main effect for time emerged, = 3.32,
t(114) = 4.62, p < .001; however, the Condition x Time interaction was not significant, = 1.34,
t(115) = 1.39, p = .17. LMM analyses within the completer sample revealed a main effect for
time, = 3.30, t(70) = 3.71, p < .001, which was qualified by a significant Condition x Time
interaction, = 3.09, t(69) = 2.47, p = .02.
PTSD diagnostic status. The influence of CBT/SUD + SWT and CBT/SUD on PTSD
symptoms from pre- to post-treatment was investigated with for PTSD, and for
partial PTSD and PTSD together. In the ITT analyses, CBT/SUD + SWT resulted in a significant
N p’s < .05. In the CBT/SUD
condition, results were significant for partial PTSD and PTSD together, (1, N = 43)
14.4, p < .001, but not for PTSD, N = 43) = 1.0, p = .32.
To investigate differences for PTSD diagnoses between CBT/SUD + SWT and CBT/SUD
at post- no
differences between the treatment groups at post-treatment for PTSD diagnostic status (p = .40).
In the completer sample CBT/SUD + SWT had a positive effect on PTSD status in
remission from pre- N 8.6, p’s < .01. For CBT/SUD
significant differences were found for PTSD diagnostic status from pre- to post-
N p’s < .05. In the completer sample, an overall showed no
between group differences in PTSD diagnostic status at post-treatment (p = .05).
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5
Tab
le 3
. Tre
atm
ent E
ffec
ts fo
r P
rim
ary
Out
com
es fo
r IT
T S
ampl
e (N
= 9
6) a
nd C
ompl
eter
Sam
ple
(N =
52)
(E
stim
ated
Val
ues)
.
Not
e. P
DS
= P
osttr
aum
atic
Dia
gnos
tic S
cale
. PT
SD =
Pos
ttrau
mat
ic s
tres
s di
sord
er. T
LFB
= T
imel
ine
Fol
low
Bac
k. C
BT
/SU
D +
SW
T =
Cog
nitiv
e be
havi
oral
trea
tmen
t for
su
bsta
nce
use
diso
rder
plu
s St
ruct
ured
Wri
ting
The
rapy
. CB
T/S
UD
= C
ogni
tive
beha
vior
al tr
eatm
ent f
or s
ubst
ance
use
dis
orde
r. I
TT
= I
nten
t to
trea
t sam
ple.
Com
pl =
Com
plet
er
sam
ple.
Pre
= P
re-t
reat
men
t. M
id =
Mid
-tre
atm
ent.
Pos
t = P
ost-
trea
tmen
t. Fu
= 3
-mon
th f
ollo
w-u
p. C
I =
Con
fide
nce
inte
rval
. **
p <
.001
. * p
< .0
1.
22
d ca
lcul
ated
wit
h ad
just
ed m
eans
at 3
-mon
th f
ollo
w-u
p co
ntro
llin
g fo
r ba
seli
ne s
core
s.
Dom
ain
Sam
ple
Pre
Mid
Pos
t
Fu
Mai
n ef
fect
(ti
me)
Inte
ract
ion
effe
ct (
grou
p *
tim
e)
t
p E
ffec
tsiz
e22 [
95%
CI]
t
p E
ffec
tsiz
e [9
5% C
I]
PTSD
sym
ptom
sev
erit
y
PDS
Tot
al
CB
T/S
UD
+ S
WT
IT
T
27.5
22
.8
18.1
13
.5
3.32
4.
62
**
-1.2
99 [
-1.7
4--0
.86]
1.34
1.
39
ns
-0.5
26[-
0.93
4--0
.12]
CB
T/S
UD
IT
T
26.0
22
.6
19.3
16
.0
CB
T/S
UD
+ S
WT
C
ompl
26
.3
19.9
13
.5
7.1
3.30
3.
71
**
-1.2
71 [
-1.8
7--0
.68]
3.09
2.
47
* -1
.192
[-1
.178
- -0
.60]
CB
T/S
UD
C
ompl
26
.9
23.7
20
.4
17.1
Num
ber
of a
bstin
ent d
ays
TL
FB
CB
T/S
UD
+ S
WT
IT
T
32.2
-
48.2
64
.1
14.6
5 4.
12
**
1.42
5 [0
.98-
1.87
]
1.29
0.
27
ns
0.12
5 [-
0.28
-0.5
3]
CB
T/S
UD
IT
T
36.8
-
51.5
66
.1
CB
T/S
UD
+ S
WT
C
ompl
35
.8
- 56
.4
77.0
17
.31
3.90
**
1.
749
[1.1
0-2.
39]
3.
26
0.51
ns
0.
329
[-0.
22-0
.88]
CB
T/S
UD
C
ompl
41
.7
- 59
.0
76.3
116_Untitled-2.job116_Proefschrift Debora van Dam.job
11
6
Tab
le 4
. Tre
atm
ent E
ffec
ts fo
r P
TSD
Dia
gnos
tic
Stat
us fo
r IT
T S
ampl
e (N
= 9
6) a
nd C
ompl
eter
Sam
ple
(N =
52)
(E
stim
ated
Val
ues)
Not
e. P
TSD
= P
osttr
aum
atic
str
ess
diso
rder
. C
BT
/SU
D +
SW
T =
Cog
nitiv
e be
havi
oral
tre
atm
ent
for
subs
tanc
e us
e di
sord
er p
lus
Stru
ctur
ed W
ritin
g T
hera
py.
CB
T/S
UD
=
Cog
nitiv
e be
havi
oral
trea
tmen
t fo
r su
bsta
nce
use
diso
rder
. IT
T =
Int
ent t
o tr
eat s
ampl
e. C
ompl
= C
ompl
eter
sam
ple.
Pre
= P
re-t
reat
men
t. P
ost =
Pos
t-tr
eatm
ent.
OR
= O
dds
rati
o.
** p
< .0
01. *
p <
.01.
23 O
R =
incr
ease
of
case
s/ d
ecre
ase
of c
ases
(b/
c) (
Bre
slow
& D
ay, 1
980)
.
Dia
gnos
tic
stat
us, n
(%)
Sam
ple
Pre
Pos
t
Pre
- to
pos
t-tr
eatm
ent
effe
ct
G
roup
eff
ect
post
-tre
atm
ent
McN
emar
s ²
p E
ffec
tsiz
e23 (
OR
)
Fi
sher
’s p
Ef
fect
size
()
Post
trau
mat
ic s
tres
s di
sord
er
PTSD
and
Par
tial P
TSD
CB
T/S
UD
+ S
WT
IT
T
53 (
100.
0)
27.2
(51
.3)
24.8
**
0
ns
-0
.130
CB
T/S
UD
IT
T
43 (
100.
0)
27.6
(64
.2)
14.4
**
0
PTSD
CB
T/S
UD
+ S
WT
IT
T
34 (
64.2
) 21
.5 (
40.6
) 5.
7 *
0.33
0
-0
.148
CB
T/S
UD
IT
T
28 (
65.1
) 23
.8 (
55.3
) 1.
0 ns
0.
533
PTSD
and
Par
tial P
TSD
CB
T/S
UD
+ S
WT
C
ompl
26
(100
.0)
8.3
(31.
9)
16.8
**
0
ns
(tr
end)
-0
.287
CB
T/S
UD
C
ompl
26
(10
0.0)
15
.6 (
60.0
) 9.
4 *
0
PTSD
CB
T/S
UD
+ S
WT
C
ompl
17
(65.
4)
6 (2
3.1)
8.
6 *
0.08
3
-0
.316
CB
T/S
UD
C
ompl
19
(73.
1)
13.9
(53
.5)
4.1
* 0
117_Untitled-2.job117_Proefschrift Debora van Dam.job
11
7
Tab
le 5
. Tre
atm
ent E
ffec
ts fo
r SU
D D
iagn
osti
c St
atus
for
ITT
Sam
ple
(N =
96)
and
Com
plet
er S
ampl
e (N
= 5
2) (
Est
imat
ed V
alue
s)
Dia
gnos
tic
stat
us, n
(%)
Sam
ple
Pre
Pos
t
Pre
- to
pos
t-tr
eatm
ent
effe
ct
G
roup
eff
ect
post
-tre
atm
ent
McN
emar
s ²
p E
ffec
tsiz
e24 (
OR
)
Fi
sher
’s p
Ef
fect
size
()
Subs
tanc
e us
e di
sord
ers
Prim
ary
SUD
CB
T/S
UD
+ S
WT
IT
T
52 (
98.1
) 27
.7 (
52.3
) 27
.0
**
0
ns
-0.0
20
CB
T/S
UD
IT
T
40 (
93.0
) 23
.5 (
54.7
) 13
.0
**
0.08
8
SUD
tota
l
CB
T/S
UD
+ S
WT
IT
T
52 (
98.1
) 29
.4 (
55.5
) 22
.0
**
0
ns
-0.0
21
CB
T/S
UD
IT
T
40 (
93.0
) 24
.8 (
57.7
) 13
.9
**
0.1
Prim
ary
SUD
CB
T/S
UD
+ S
WT
C
ompl
25
(96
.2)
8.2
(31.
5)
15.9
**
0
ns
-0
.207
CB
T/S
UD
C
ompl
23
(88
.5)
13.4
(51
.5)
6.5
* 0.
143
SUD
tota
l
CB
T/S
UD
+ S
WT
C
ompl
25
(96
.2)
8.6
(33.
1)
15.5
**
0
ns
-0
.192
CB
T/S
UD
C
ompl
23
(88
.5)
13.5
(51
.9)
6.5
* 0.
143
Not
e. S
UD
= S
ubst
ance
use
dis
orde
r. C
BT
/SU
D +
SW
T =
Cog
nitiv
e be
havi
oral
tre
atm
ent
for
subs
tanc
e us
e di
sord
er p
lus
Stru
ctur
ed W
ritin
g T
hera
py.
CB
T/S
UD
= C
ogni
tive
beha
vior
al t
reat
men
t fo
r su
bsta
nce
use
diso
rder
. IT
T =
Int
ent
to t
reat
sam
ple.
Com
pl =
Com
plet
er s
ampl
e. P
re =
Pre
-tre
atm
ent.
Pos
t =
Pos
t-tr
eatm
ent.
OR
= O
dds
rati
o. *
* p
< .0
01. *
p <
.01.
24 O
R =
incr
ease
of
case
s/ d
ecre
ase
of c
ases
(b/
c) (
Bre
slow
& D
ay, 1
980)
.
118_Untitled-2.job118_Proefschrift Debora van Dam.job
118
Reliable change index. The reliable change index was calculated for the PDS (Jacobson
& Truax, 1991) ITT and 0.86 for the completer sample. Using the
RCI as a criterion, 58.1% of the ITT sample randomized to CBT/SUD + SWT and 54.9%
randomized to CBT/SUD achieved reliable change. Within the completer sample the percentages
for reliable change were 78.5% for CBT/SUD + SWT and 53.8% for CBT/SUD.
Effect of Treatment on SUD
The outcome measures for SUD were the number of abstinent days (TLFB) and SUD
diagnostic status (SCID diagnosis). Descriptive analyses and effect sizes are displayed in Tables
3 and 5.
Abstinence. Overall a
TLFB reports for a 90 day time window. In the ITT sample, there was a significant increase over
time from pre-treatment to follow-up for the number of drug- and alcoholfree days, = 14.65,
t(95) = 4.12, p < .0001, but no significant Condition x Time interaction, = 1.29, t(95) = 0.27, p
= .79.
Similarly, completer analyses showed a significant increase over time from pre- treatment
to follow-up = 20.57, t(141) = 4.53, p < .0001. However, no Condition x Time interaction
effect was found, = 3.26, t(141) = 0.51, p = .61.
For both samples outcomes were similar after logtransformation
SUD diagnostic status. To compare SUD diagnostic status from pre- to post-treatment in
ITT and the
completer sample.
ITT analyses showed a significant decrease of SUD diagnoses from pre- to post-treatment
N p’s < .001, N =
p’s < .001. In the ITT sample, no significant differences were found for SUD diagnostic
status between CBT/SUD + SWT and CBT/SUD at post-treatment exact test, p’s >
.84).
Completer analyses showed a significant decrease of SUD diagnoses for both treatment
groups. Outcomes showed (1, N = 53) p’s < .001) for SWT+CBT/SUD,
N , p < .05 for CBT/SUD. Post-treatment analyses for
119_Untitled-2.job119_Proefschrift Debora van Dam.job
119
completers yielded no significant differences for SUD diagnostic status between CBT/SUD +
SWT and CBT/SUD exact test, p’s > .26).
Reliable change index. The reliable change index was calculated for the TLFB (Jacobson
& Truax, 1991) ITT and the completer sample. Within the
ITT sample, the percentages for reliable change were 62.3% for CBT/SUD + SWT and 59.5% for
CBT/SUD. In the completer sample, 69.2% of the patients randomized to CBT/SUD + SWT
achieved reliable change, compared to 67.7% of the patients randomized to CBT/SUD.
Discussion
This study was one of the first RCTs investigating trauma-focused PTSD treatment for
patients with concurrent PTSD and SUD. The purpose of this RCT was to determine the clinical
effectiveness (Flay, 1986) of an integrated trauma-focused treatment for PTSD and SUD
(CBT/SUD + SWT), compared with TAU for SUD (CBT/SUD) within an outpatient sample with
concurrent PTSD and SUD.
According to the first hypothesis, it was expected that both treatments would be effective
in decreasing symptoms of SUD and PTSD. For the most part, this hypothesis was supported by
treatment results in both the ITT and the completer sample. In both types of analyses, CBT/SUD
+ SWT and CBT/SUD were effective in reducing PTSD symptoms and the use of substances
from pre-treatment to 3-month follow-up. Both treatments also significantly reduced SUD
diagnostic status in participants. A decrease of PTSD diagnostic status was also noticed in both
treatments, except for the PTSD diagnoses after CBT/SUD in the ITT sample.
According to the second hypothesis, it was expected that CBT/SUD + SWT would be
significantly more effective than CBT/SUD in reducing symptoms of PTSD. Results from the
ITT sample did not support this hypothesis, as reductions in PTSD symptom severities or PTSD
diagnoses did not differ significantly between conditions. However, completer analyses favored
CBT/SUD + SWT over CBT/SUD in reducing PTSD symptom severity from pre-treatment to 3-
month follow-up. Also, in the completer sample a trend was noticed for more remitted PTSD
cases after CBT/SUD + SWT than after CBT/SUD at post-treatment. These outcomes indicate
that the combined treatment was superior to regular SUD treatment if patients completed a
substantial part of their treatment (at least 75% of the treatment sessions).
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120
Finally, it was hypothesized that CBT/SUD + SWT would be more effective in reducing
symptom levels of SUD than CBT/SUD alone. This hypothesis was not supported. In the
CBT/SUD + SWT and the CBT/SUD group, the number of abstinent days increased to a similar
degree. In addition, no superior improvements for SUD diagnostic status were found in the
CBT/SUD + SWT condition compared with the CBT/SUD condition.
In sum, PTSD and SUD symptoms were treated effectively in both conditions. However,
outcomes in the completer sample indicate that patients benefitted more from CBT/SUD + SWT
than from CBT/SUD. The difference in results for ITT versus completer analyses suggests that a
superior effect of the integrated treatment is achieved only if a crucial number of trauma-focused
PTSD treatment sessions have been attended. Trauma-focused CBT for PTSD usually comprises
10 sessions or more (Resick & Schnicke, 1992; Van Emmerik, 2008). It is therefore conceivable
that attending less than six sessions of SWT, which led to participants being classified as non-
completers, is not sufficient for individuals suffering from both PTSD and SUD. Based on these
results it seems recommendable to inform patients with concurrent PTSD and SUD carefully
about the importance of finishing an integrated trauma-focused treatment, before they decide to
begin one, and to explore treatment motivation in advance, especially since a lack of motivation
was reported as the main reason for drop out.
Contrary to our hypotheses, both treatments were equally effective in treating SUD.
Based on the assumption that PTSD symptoms are a risk for the relapse in substance use, we had
expected superior improvements for SUD after integrated PTSD and SUD treatment. A number
of possible explanations for this finding are conceivable. First, CBT/SUD was highly effective,
leading to a large decrease in substance use. This can be expected to have reduced the chance to
find incremental efficacy in the integrated treatment condition. Second, CBT/SUD already led to
a decrease of PTSD symptoms. Although this change was significantly lower than in the
CBT/SUD + SWT condition, it may have been sufficient to reduce the chance for relapse.
Notably, these findings resemble the outcomes for other studies investigating the effectiveness of
integrated treatment for PTSD and SUD (Hien et al., 2004; Cohen & Hien, 2006; Hien et al.,
2009; Zlotnick, Johnson, & Najavits, 2009). Finally, it is possible that differences between the
two conditions on SUD outcome may only show at longer follow-up intervals in that individuals
in the integrated show less relapse in the long run than those who had received TAU. A long-term
follow-up (e.g., 12-month follow-up) testing this idea is currently underway.
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The main focus in this study was the clinical effectiveness (Flay, 1986) of SWT +
CBT/SUD compared with CBT/SUD. This has practical advantages above a strictly academic
approach, where treatment efficacy is investigated under optimal conditions of delivery (Flay,
1986). To serve this purpose we strived for an optimal resemblance of study procedures with
routine clinical care. Firstly, the study was implemented under the usual circumstances, using
regular SUD treatment staff. Secondly, SWT was chosen as an intervention for PTSD. An
important positive feature of SWT was its easy administration within routine clinical practice.
SWT could be carried out by SUD therapists with none or little experience in PTSD treatment,
after a two hour training only. Thirdly, the TAU intervention was not adapted for research
purposes. Therefore the length of the 10-sessions TAU intervention (CBT/SUD), was not
artificially extended. As a consequence CBT/SUD + SWT was 5 sessions longer then TAU, as it
was not possible to fit the integrated treatment protocol in 10 sessions. Although both treatments
were spread over a period of 15 weeks, patients receiving CBT/SUD + SWT had more frequent
contact with their therapist. Consequently, this complicates the interpretation of research
findings. For example, a higher treatment dose may have influenced the outcomes for CBT/SUD
+ SWT (Gibbons et al., 2010; Luborsky et al., 2002), and it cannot be ruled out that this non-
specific treatment element explains the favorable results of CBT/SUD + SWT on PTSD
symptoms. Alternatively, the lack of differences in SUD outcome between the two conditions
could be due to the fact that a possible effect of SWT on SUD may have been compensated by a
reduced number of CBT/SUD sessions (Ouimette et al., 1998). These complications in the
interpretation of the results seem justifiable for the sake of clinical effectiveness. Moreover, the
fact that two protocols were compared that directly reflected interventions offered in clinical
practice, mirrors an important strength of the current study. Another strength of this study was the
standardization of the interventions, by the exclusion of alternative psychological care and the
uniform control treatment. This was done to determine the effect of the experimental treatment
CBT/SUD + SWT compared to CBT/SUD more specifically, and it is a positive feature in
comparison to some other RCTs in this research area (Hien et al., 2009; Killeen et al., 2008; Mills
et al., 2012; Najavits et al., 2006).
This study also revealed more information about treatment adherence for trauma-focused
PTSD treatment within this patient group. High dropout is a common concern for trauma-focused
interventions in the treatment of concurrent PTSD and SUD (Brady et al., 2001; Coffey et al.,
122_Untitled-2.job122_Proefschrift Debora van Dam.job
122
2006; Hien et al., 2009; Van Dam et al., 2012). In this study, the dropout percentage was 46%. It
is difficult to compare this percentage with other treatments for concurrent PTSD and SUD,
because treatment completers are not universally defined across various studies (Van Dam et al.,
2012). However, the dropout percentages, and reasons for dropout were equal in both treatment
conditions of this study. These findings contradict possible concerns that trauma-focused therapy
in the treatment of concurrent PTSD and SUD increases the incidence of dropout (Brady et al.,
2001; Coffey et al., 2006). Still, dropout percentages are high, and future research is needed to
investigate ways to improve treatment adherence for this outpatient group.
This study has also some limitations. First, as the study was performed in an outpatient
setting, it is unclear to what extent the results can be generalized to more severe SUD patients.
However, the effectiveness of SWT combined with CBT for severe SUD patients has been
investigated in a clinical study recently (Van Dam, Ehring, Vedel, & Emmelkamp, 2013b).
Second, the treatment sessions were not recorded to determine treatment adherence, but therapists
were monitored carefully during weekly supervisions and by the reading of session reports.
Third, no urine or blood tests were performed to confirm the self-reported substance use. Still,
there are indications for high congruence between self-report and physical tests (Calhoun et al.,
2000; Sherman & Bigelow, 1992). In addition, the assessment of substance use was not
conducted by the therapists, but by an independent assessor. Therefore there are no particular
reasons to assume that the patients in our study felt the need to cover their substance use in order
to keep up appearances.
To conclude, the outcomes of the current study appear hopeful. They give a modest
indication that CBT/SUD + SWT is favorable to SUD treatment alone in treating concurrent
PTSD and SUD provided that patients receive enough treatment sessions (i.e. at least 75%). The
results are in line with other positive findings for trauma-focused treatment for patients with
concurrent PTSD and SUD (Brady et al., 2001; Mills et al., 2012). Furthermore, no indications
were found for symptom exacerbation and adverse events after trauma-focused treatment,
including increased dropout. Still, it is too soon to draw firm conclusions about the relative
effectiveness of CBT/SUD + SWT, or trauma-focused treatment in general, within this patient
group. Future research is needed to replicate and extend these findings before dissemination of
this treatment approach is warranted (Breslow & Day, 1980).
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CChapter 6
Trauma-focused treatment for posttraumatic stress
disorder combined with CBT for severe substance use
disorder: a randomized controlled trial
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Abstract
This randomized controlled trial (RCT) investigated the effectiveness of a combined
treatment for co-morbid posttraumatic stress disorder (PTSD) and severe substance use disorder
(SUD). Structured Writing Therapy for PTSD (SWT), an evidence-based trauma-focused
intervention, was added on to treatment as usual (TAU), consisting of an intensive cognitive
behavioral inpatient or day group treatment for SUD. The outcomes of the combined treatment
(TAU + SWT) were compared to TAU alone in a sample of 34 patients. Results showed a general
reduction of SUD symptoms for both TAU + SWT and TAU. Treatment superiority of TAU +
SWT was neither confirmed by interaction effects (time x condition) for SUD or PTSD
symptoms, nor by a group difference for SUD diagnostic status at post-treatment. However,
planned contrasts revealed that improvements for PTSD severity over time were only significant
within the TAU + SWT group. In addition, within the TAU + SWT group the remission of PTSD
diagnoses after treatment was significant, which was not the case for TAU. Finally, at post-
treatment a trend was noticed for between group differences for the number of PTSD diagnoses
favoring TAU + SWT above TAU. In sum, the current study provides preliminary evidence that
adding a trauma-focused treatment on to standard SUD treatment may be beneficial.
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Introduction
Over the past decade, the detection and treatment of posttraumatic stress disorder (PTSD)
among substance use disorder (SUD) patients have been studied increasingly (Kimerling,
Trafton, & Nguyen, 2006; Van Dam, Ehring, Vedel, & Emmelkamp, 2010; Van Dam, Vedel,
Ehring, & Emmelkamp, 2012). This trend mirrors a need in clinical practice as the number of
SUD patients meeting diagnostic criteria for PTSD is relatively large (20-30%) (Kimerling et al.,
2006; Van Dam et al., 2010). Importantly, there is evidence that this patient group suffers from
more severe complaints and more relapses in substance use than SUD patients without comorbid
PTSD (Back et al., 2000; Najavits, Weiss & Shaw, 1999). This suggests that the common
treatment approach, whereby SUD and PTSD are treated sequentially and within different
treatment centers, may not be optimal (Ford, Russo, & Mallon, 2007; McGovern et al., 2009;
Najavits et al., 2007).
Several theories have been developed to explain the high comorbidity between PTSD and
SUD. Most evidence is available for the self-medication theory (Khantzian, 1985), which
suggests that substances are used to alleviate or suppress PTSD symptoms. In line with this
theory, research investigating the chronology of PTSD and SUD has shown that SUD is preceded
by PTSD more often than vice versa (Stewart & Conrod, 2003; Watt et al., 2012), that the
exacerbation of PTSD symptoms is the most important factor in predicting relapse following
SUD treatment (Clark, Masson, Delucchi, Hall, & Sees, 2001), and that improvements in PTSD
symptoms are associated with subsequent improvements in substance dependence (Back, Brady,
Sonne, & Verduin, 2006; Hien et al., 2010). In addition, experimental research suggests that
trauma-related cues can trigger a craving response (Coffey et al., 2002).
On the other hand, there are also theoretical and empirical grounds to assume an inverse
relationship. The high risk hypothesis poses that SUD augments the risk for traumatic
experiences and thereby the chance for developing PTSD (Hien, Cohen, & Campbell, 2005). In
addition, SUD may interfere with extinction of the trauma memory (Stewart & Conrod, 2003),
and the withdrawal of substances may evoke traumatic memories and trigger PTSD symptoms as
it resembles physical experiences during trauma (Stewart & Conrod, 2003). In line with these
hypotheses, there is some evidence to suggest that in some cases SUD precedes PTSD in the
development of this comorbidity; in addition, the treatment of SUD alone has been shown to lead
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to a reduction of PTSD symptoms (Cohen & Hien, 2006; Hien, Cohen, Miele, Litt, & Capstick,
2004; Hien et al., 2009; Zlotnick, Johnson, & Najavits, 2009).
Taken the two perspectives together, a reciprocal relationship between both disorders
appears to be the most likely explanation for the high co-morbidity between PTSD and SUD
(Stewart & Conrod, 2003; Van Dam et al., 2012). This hypothesis is also supported by recent
data indicating that the vast majority of patients first reported trauma, then substance use, which
again was followed by additional traumatic experiences, and further substance use ( McGovern,
Lambert-Harris, Alterman, Xie, & Meier, 2011). This chronology suggests that patients
substance use indeed increases after having experienced trauma, and that high levels of substance
use may in turn increase the risk for other traumatic events. A mutual relationship between PTSD
and SUD implies that PTSD symptoms may exacerbate in the first period of abstinence, and that
PTSD complaints may improve when abstinence is maintained. Consequently, it appears likely
that a sequential treatment approach increases the risk that patients drop out of SUD treatment
prematurely and therefore do not receive PTSD treatment either. It is therefore plausible to
assume that patients will benefit more from combined treatment interventions for PTSD and
SUD.
Existing treatments for concurrent PTSD and SUD are based on two different approaches.
Some authors suggest that PTSD among SUD patients should be treated according to the
guidelines for PTSD in general, which recommend trauma focused-cognitive behavioral
treatment (TF-CBT) and EMDR (National Collaborating Centre for Mental Health, 2005). An
important element of TF-CBT is trauma-focused exposure. Patients are asked to revisit their
traumatic event in their imagination and describe it in great detail (Foa, Hembree, & Rothbaum,
2007). In EMDR, the client is instructed to focus on the traumatic memory and simultaneously
perform rhythmic eye movements (Shapiro, 2001).
A contrasting point of view is that trauma-focused interventions may be too invasive for
patients with concurrent PTSD and SUD, and that these interventions put patients at risk for
relapse, treatment dropout and other adverse events (Najavits, 2004; Pitman et al., 1991). Based
on this idea, non-trauma-focused interventions have been developed that focus on the present or
t do not require patients to revisit or
reprocess the trauma (e.g. Najavits, 2004). The aim of these treatments is to provide patients with
coping skills to manage their trauma symptoms and to improve functioning. The majority of
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treatments developed for concurrent PTSD and SUD to date are non-trauma-focused (Donovan,
Padin-Rivera, & Kowaliw, 2001; McGovern et al., 2009; Najavits et al., 2003; Triffleman,
Carroll, & Kellogg, 1999). Although some programs include in vivo exposure (Triffleman et al.,
1999) or sharing traumatic experiences within the group (Donovan et al., 2001), they are best
characterized as non-trauma-focused treatments as they do not comprise exposure to the trauma
memory as a main ingredient. Existing integrated treatments using a non-trauma-focused
approach appear to be successful in reducing PTSD and SUD symptoms, but their results are
generally not superior to active control conditions, such as regular SUD treatment (Boden et al.,
2012; McHugo & Fallot, 2011; Van Dam et al., 2012). However, integrated cognitive behavioral
therapy, a non-trauma-focused therapy based on a cognitive restructuring approach, appears to be
a positive exception to this rule (McGovern et al., 2011).
Recent evidence suggests that patients with concurrent PTSD and SUD may benefit
from trauma-focused interventions, and that these interventions are more effective in reducing
symptoms of PTSD than treatment-as-usual (TAU) (Coffey, Stasiewicz, Hughes, & Brimo, 2006;
Mills et al., 2012; Van Dam, Vedel, Ehring, & Emmelkamp, submitted; Van Dam et al., 2012).
Importantly, it appears that exposure-based interventions are not necessarily associated with an
increase in attrition or relapse to drugs or alcohol (Brady, Dansky, Back, Foa, & Carroll, 2001;
Van Dam et al., submitted). Until now, trauma-focused interventions have not been studied
within severe SUD patients allocated to intensive SUD treatment. Attention for PTSD symptoms
appears especially important for this patient group as untreated PTSD symptoms can be expected
to be related to a number of clinical complications. Earlier research has shown that PTSD
symptoms in SUD patients are associated with increased relapse in substance use (Back et al.,
2006; Norman, Tate, Anderson, & Brown, 2007; Read, Brown, & Kahler, 2004), and with more
problems in mental health, physical health, and social relationships (Najavits et al., 1998). To our
knowledge, this randomized controlled trial (RCT) is the first study bridging this gap.
An evidence-based trauma-focused intervention for PTSD was added on to a regular
intensive cognitive behavioral SUD program for severe SUD patients, which was the TAU for
this sample (Emmelkamp, & Vedel, 2006). The study aimed to investigate the effectiveness of
adding PTSD treatment to the intensive SUD treatment program compared to TAU, i.e. the
intensive SUD treatment program only. The trauma-focused intervention was Structured Writing
Therapy (SWT) for PTSD (Van Emmerik, Kamphuis, & Emmelkamp, 2008). SWT uses specific
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writing assignments to reprocess painful trauma memories, and it encourages cognitive
reappraisal of trauma-related thoughts and social sharing of the traumatic event. Results from
several studies support the effectiveness of SWT in the treatment of PTSD (Lange et al., 2003;
Lange, Van de Ven, Schrieken, & Emmelkamp, 2001; Van Emmerik et al., 2008). In addition,
SWT has been shown to reduce levels of intrusions and avoidance, depression, anxiety and
somatization (Lange et al., 2003).
The current study originated from an RCT investigating the effectiveness of an integrated
outpatient treatment for concurrent PTSD and SUD (Van Dam et al., submitted). In comparison
to that study, the current investigation focused on patients with more severe SUD symptoms who
were attending inpatient or day treatment. Furthermore, in contrast to the study among outpatients
SWT was not integrated into the SUD intervention, but added on to TAU. The patients
randomized to the experimental condition (TAU + SWT) received 10 individual sessions of SWT
in addition to the regular SUD program. An add-on approach seemed more appropriate for this
study as SWT is provided as an individual therapy. By adding SWT on to the regular SUD
program, all patients received the same group intervention for SUD. Therefore, they all benefited
equally from group dynamics, and they all received the same dose of SUD treatment whether
they were allocated to TAU or TAU + SWT.
The aim of this RCT was to investigate the effectiveness of a combined treatment for
comorbid PTSD and severe SUD. Three hypotheses were tested. The first hypothesis was based
on the theory that PTSD and SUD are reciprocally related. In line with this assumption, we
expected that both TAU and TAU + SWT would be effective in decreasing symptoms of SUD
and PTSD. Secondly, we expected that patients receiving TAU + SWT would achieve
significantly higher improvements on PTSD symptoms than patients in the TAU condition.
Thirdly, following from the self-medication hypothesis we hypothesized that TAU + SWT would
be more effective in reducing symptoms of SUD than TAU alone.
Method
Participants
Figure 1 summarizes the flow of participants through the study. A consecutive sample of
34 patients was recruited from the Jellinek Substance Abuse Treatment Center in Amsterdam,
The Netherlands. All patients were allocated to intensive inpatient or day group treatment for
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SUD. Allocation for treatment followed the principles of stepped care. Therefore, all patients
included in the current study suffered from severe substance abuse, and had already been
allocated to two or more SUD therapies in the past five years. Three patients dropping out the
study investigating integrated outpatient treatment for concurrent PTSD and SUD (Van Dam et
al., submitted) were also included into the current study. Recruitment and eligibility criteria were
parallel to the study among outpatients (Van Dam et al., submitted). Patients were recruited
between July 2008 and July 2011. Inclusion criteria were: (1) a diagnosis of substance abuse or
substance dependence according to the Diagnostic and Statistical Manual (DSM-IV; American
Psychiatric Association [APA], 1994), (2) a diagnosis of full-blown or partial PTSD according to
DSM-IV (partial PTSD was defined as meeting symptom criteria for the reexperiencing cluster
and for either the avoidance/numbing cluster or the hyperarousal cluster) (Blanchard, Hickling,
Taylor, Loos, & Gerardi, 1994), (3) being allocated to intensive group treatment either as day
treatment or as in-patient, (4) being 18 years or older, and (5) sufficient understanding of the
Dutch or English language. Exclusion criteria were (1) a diagnosis of borderline personality
disorder (BPD), (2) other severe (psychiatric) problems that required immediate clinical care
(e.g., psychotic symptoms, manic episode, current suicidal ideation, severe domestic violence),
(3) severe cognitive disorders, or (4) receiving concurrent psychotherapy for any kind of
psychological disorder. Patients receiving medication for psychological complaints (e.g.,
antidepressant medication) were included in the study if they remained on a stable dose during
the course of the study. This was the case for six patients (18%). At 3-month follow-up, patients
were asked whether there had been any change in medication prescription during the follow-up
interval. One patient (3%) reported a change in medication treatment between post-treatment and
follow-up, and two patients (6%) reported to have started new medication treatment within a
month after treatment. No group differences were found between the TAU + SWT and TAU
condition for the number of patients using medication during treatment, or medication changes
p’s > .245).
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Figure 1. CONSORT flowchart of the recruitment and retention of participants. t1= baseline, t2 = mid-treatment, t3 = post-treatment; t4= 3-month follow-up, ITT= Intent to treat.
36 t1 (pre-treatment)
16 completed t2 (mid-treatment) 14 completed t3 (post-treatment) 14 completed t4 (3 mo follow-up)
19 in ITT analyses
11 completed t2 (mid-treatment) 13 completed t3 (post-treatment) 13 completed t4 (3 mo follow-up)
15 in ITT analyses
19 TAU + SWT 9 dropout
15 TAU 4 dropout
508 positive PTSD screens
42 eligible
6 declined (did not want to participate)
36 randomly allocated
34
2 patients referred to TAU withdrew from study after randomization.
466 ineligible 205 no (subthreshold) PTSD
141 allocated to outpatient treatment 44 severe (psychiatric) problems 23 concurrent psychotherapy 23 borderline personality disorder 4 severe cognitive problems 5 language
17 other 4 unknown
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Patients in both conditions were considered dropouts if they ended TAU for SUD
prematurely. Patients in the TAU + SWT group were additionally labeled as dropout if they
attended less than 75% of the SWT treatment session
(N = 19) revealed that ten patients completed treatment (53%). The other nine patients ended
treatment before the fifth SWT session (47%). Three of them dropped out of treatment even
before SWT started (33%). In this study, non-response was not equal to treatment dropout, as all
patients could participate in study measurements whether they completed treatment or not.
Tables 1 and 2 summarize sample characteristics and between group analyses. The overall
sample consisted of 23 males and 11 females, with a mean age of 42.3 (SD = 9.0). No significant
differences between treatment conditions were found for sample characteristics, or dropout rates
²’s (1, N = 34) 3.03, p’s .22. In addition, no group differences were revealed for baseline
symptom severities t 0.62, p’s .54 p’s
Treatments
Treatment as usual (TAU) consisted of a regular intensive treatment program for SUD
based on the principles of cognitive behavioral treatment (CBT) (Emmelkamp & Vedel, 2006).
The treatment was delivered in a group format, and included coping skill training for alcohol
and/or drug abuse, an evidence-based treatment for SUD (Emmelkamp, & Vedel, 2006).
Coping skill training for SUD teaches patients to recognize high risk situations preceding
substance use, and offers strategies to deal with craving and relapse. Training tools are modeling,
behavioral practice and homework assignments (Monti, Kadden, Rohsenow, Cooney, & Abrams,
2002). Coping skills training for SUD was offered twice a week for the first six weeks (2 h group
sessions). After that, weekly sessions were provided for a period of 8 weeks. Furthermore, TAU
incorporated social skills training, relaxation training, psycho-education, motivational
interviewing sessions, basic CBT-training, relapse prevention sessions and emotion-regulation
training. In addition to attending the group training program, patients had weekly sessions with
an individual therapist. No interventions related to PTSD symptoms were carried out during these
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Table 1. Sample Characteristics.
Demographics
Total
(n = 34)
TAU + SWT
(n = 19)
TAU
(n = 15)
Between group
Analyses
Mean age (SD) 42.3 (9.0) 42.6 (8.4) 41.9 (10.0) t (33) = 0.21, p = .84
Gender, n (%) p = .92
Male 23 (67.6) 13 (68.4) 10 (66.7)
Female 11 (32.4) 6 (31.6) 5 (33.3)
Ethnicity, n (%) p = .56
Dutch 23 (67.6) 13 (68.4) 10 (66.7)
European (other) 2 (5.9) 1 (5.3) 1 (6.7)
Arabic/ Moroccan/ Turkish 4 (11.8) 1 (5.3) 3 (20.0)
Black/ Surinamese/ Caribbean 4 (11.8) 3 (15.8) 1 (6.7)
Other 1 (2.9) 1 (5.3) 0 (0)
Education (certificate), n (%) p = .94
No education, primary school 11 (32.4) 6 (31.6) 5 (33.3)
Secondary school, lower level 8 (23.5) 4 (21.1) 4 (26.7)
Secondary school, higher level 9 (26.5) 5 (26.3) 4 (26.7)
Postsecondary 6 (17.6) 4 (21.1) 2 (13.3)
Relationship status, n (%) p = .24
Single 31 (91.2) 17 (89.5) 14 (93.3)
Partner 2 (5.9) 2 (10.5) 0 (0)
Missing 1 (2.9) 0 (0) 1 (6.7)
Source of income, n (%) p = .22
No work 22 (64.7) 10 (52.6) 12 (80)
Work 11 (32.4) 8 (42.1) 3 (20)
Missing 1 (2.9) 1 (5.3) 0 (0)
Dropouts, n (%)
SUD treatment & SWT 13 (38.2) 9 (47.4) 4 (26.7) p = .30
SUD treatment 12 (35.3) 8 (42.1) 4 (26.7) p = .48
Baseline Measures
Mean PDS (SD) 29.5 (10.0) 30.4 (9.7) 28.3 (10.7) t (33) = 0.62, p = .54
Mean TLFB (SD) 20.0 (27.2) 19.9 (29.3) 20.1 (25.4) t (33) = 0.19, p = .99
Note. TAU = Treatment as usual; SWT = Structured Writing Therapy. SUD = Substance use disorder. PDS = Posttraumatic Diagnostic Scale. TLFB = Timeline Follow Back. * Level of education: secondary school, lower level = VBO/LBO/MAVO/Avo; secondary school, higher level = HAVO, VWO, MBO; postsecondary = HBO, university, doctor of philosophy.
141_Untitled-2.job141_Proefschrift Debora van Dam.job
141
individual treatment sessions. The duration of the intensive part of the treatment program varied
from 6 to 12 weeks. On average, patients attended the program four days a week. Dependent on
the individual needs of each patient, TAU could be followed on an inpatient or an outpatient (day
treatment) basis. All patients followed a detoxification program before starting the treatment
program.
TAU + SWT existed of the same treatment program as described above, except for ten
individual sessions of SWT that were added on to the program. SWT started after patients had
been abstinent for 4 to 6 weeks. The treatment was drawn from a former protocol (Van Emmerik,
2004). Therapy sessions were offered weekly and lasted 45-60 min. SWT consists of the
Table 2. Sample Characteristics: Diagnostic Status (Current)
Diagnostic status
Total
(n = 34)
TAU + SWT
(n = 19)
TAU
(n = 15)
Between group
Analyses (Fisher’s exact)
PTSD diagnosis (full-blown), n (%) 21 (61.8) 9 (47.4) 12 (80.0) p = .08
Primary SUD diagnosis, n (%)
Alcohol, not in remission 16 (44.1) 11 (57.9) 5 (33.3) p = .19
Drugs, not in remission 15 (44.1) 8 (42.1) 7 (46.7)
Cannabis 4 (11.8) 1 (5.3) 3 (20.0) p = .30
Cocaine 10 (29.4) 6 (31.6) 4 (26.7) p = 1.0
Other 1 (2.9) 1 (5.3) 0 (0) p = 1.0
Substance Dependence 30 (88.2) 18 (94.7) 12 (80.0) p = .30
Substance Abuse 1 (2.9) 1 (5.3) 0 (0) p = 1.0
Other axis I diagnoses, n (%)
Depressive disorder 11 (32.4) 4 (21.1) 7 (46.7) p = .15
Panic disorder 3 (8.8) 1 (5.3) 2 (13.3) p = .57
Panic disorder with agoraphobia 2 (5.8) 0 (0) 2 (13.3) p = .19
Social Phobia 4 (11.8) 2 (10.5) 2 (13.3) p = 1.0
Specific phobia 2 (5.8) 1 (5.3) 1 (6.7) p = 1.0
Obsessive compulsive disorder 0 (0) 0 (0) 0 (0) -
General anxiety disorder 1 (2.9) 0 (0) 1 (6.7) p = .44
Eating disorder 0 (0) 0 (0) 0 (0) -
Note. TAU = Treatment as usual. SWT = Structured Writing Therapy. PTSD = Posttraumatic stress disorder. SUD = Substance use disorder.
142_Untitled-2.job142_Proefschrift Debora van Dam.job
142
following three phases: self-confrontation, cognitive reappraisal and sharing/farewell. The self-
confrontation phase comprised trauma-focused exposure, and guided patients to write in detail
about the most traumatic event(s) they had experienced. The writing had to be in the first person
and in the present tense, addressing sensory experiences, painful facts, thoughts and emotions
experienced during the trauma. The phase of cognitive reappraisal focused on changing
dysfunctional appraisals related to the traumatic event and its consequences. For this purpose,
patients were asked to write a letter of advice to an (imaginary) friend or loved one, imagining
that they had experienced the same event. Patients were asked to give advice to this person on
how to handle thoughts, emotions and consequences related to the trauma. In a second step, the
patient was instructed to write a similar letter to him- or herself. The final phase consisted of a
final letter, the patient reflected on the trauma, on its impact on life, and on
resolutions for dealing with the trauma in the future. During the whole treatment, writing
assignments were introduced and discussed during the treatment sessions. TAU + SWT also
incorporated two flexible sessions. Patients and therapists could decide what of the former SWT
assignments they wanted to give extra attention. If necessary, it was possible to use the flexible
sessions in advance to prolong the self-confrontation or the cognitive reappraisal phase.
In order to prepare patients with concurrent PTSD and SUD for possible difficulties
during detoxification and SUD treatment, psycho-education about the vicious circle of PTSD and
SUD was provided in the first treatment session (Ford et al., 2007). For ethical reasons, psycho-
education was not only provided in the TAU + SWT condition, but also in the TAU condition.
Patients in the TAU + SWT group received psycho-education from their SWT therapist. In the
TAU condition, psycho-education was provided by the individual TAU therapist.
All SWT therapists were regular therapists
clinical psychology and additional formal training in cognitive behavioral therapy. Therapist
treatment adherence was monitored in weekly supervision sessions by the last author.
Measures
The outcome measures for PTSD and SUD were change in the severity of PTSD
symptoms and change in substance use, respectively. Further outcome measures were PTSD and
SUD diagnostic status. The Posttraumatic Diagnostic Scale (PDS) (Foa, Cashman, Jaycox, &
143_Untitled-2.job143_Proefschrift Debora van Dam.job
143
Perry, 1997) was used to assess PTSD symptom severity. The PDS consists of 17 items
corresponding to the DSM-IV PTSD, that are rated on a 4-point Likert-scale (0 = not at all or only
one time; 3 = five or more times a week/almost always), and 9 items assessing impairment in
different life areas. PTSD symptom severity scores are obtained by summing the 17 symptom
items, with higher scores indicating greater symptomatology (Foa et al., 1997). The PDS has
shown to perform well within an SUD population, revealing excellent internal consistency, good
test re-test reliability, and good convergent validity with PTSD diagnosis (Powers, Gillihan,
Rosenfield, Jerud, & Foa, 2012). Also, high sensitivities, and moderate specificities were found
for the PDS within this population (Powers et al., 2012; Van Dam et al., 2010). By means of the
Timeline Follow Back (TLFB) (Sobell & Sobell, 1996), retrospective estimates of daily use of
alcohol and drugs were obtained for a time frame of 90 days. Its psychometric characteristics for
alcohol use have been extensively evaluated (Fals-
Rutigliano, 2000; Vakili, Sobell, Sobell, Simco, & Agrawal, 2008).
DSM-IV axis I disorders, including SUD and PTSD, were assessed with the Structured
Clinical Interview for DSM-IV axis I Disorders (SCID-I) (First, Spitzer, Gibbon, & Williams,
1996; Van Groenestijn, Akkerhuis, Kupka, Schneider, & Nolen, 1999). The SCID-I has shown a
fair interrater agreement for the SUD module (kappa= 0.65), and an excellent interrater
agreement for the PTSD module (kappa= 0.77) (Lobbestael, Leurgans, & Arntz, 2010). To
screen for (partial) PTSD, the Jellinek-PTSD screening questionnaire (J-PTSD) was used (Van
Dam, Ehring, Vedel, & Emmelkamp, 2013). The J-PTSD was specifically developed to screen
for PTSD in SUD patients. The sensitivity (.87), specificity (.75), and overall efficiency (.77) are
high using a cutoff score of 2 (Van Dam et al., 2013). The McLean Screening Instrument for
Borderline Personality Disorder (MSI-BPD) (Zanarini et al., 2003) was used to screen for
borderline personality disorder (BPD). The MSI-BPD has shown a good sensitivity (.81) and
specificity (.85) for a cutoff score of 7 (Zanarini et al., 2003). Patients with a score of
invited for further assessment. BPD was assessed with the Structured Clinical Interview for
DSM-IV axis II Disorders (SCID-II) (Weertman, Arntz, & Kerkhofs, 2000). The SCID-II has
shown very high interrater agreement for the BPD module (kappa= 0.91) (Lobbestael et al.,
2010).
144_Untitled-2.job144_Proefschrift Debora van Dam.job
144
Procedures
All patients attending a regular intake at the Jellinek were screened with the J-PTSD. If
the screener was positive, patients were invited for further assessment in order to determine
diagnostic status. If a formal diagnosis for (partial) PTSD was obtained, eligible patients received
written information about the study and gave written informed consent. Patients willing to
participate were invited again for the pre-treatment assessment (t1). After pre-treatment
assessment, patients were randomly assigned to either TAU + SWT or TAU by asking them to
draw one out of two closed envelopes. Each patient was approached for an additional three
assessments during the study: mid-treatment (t2) (after the fifth session), post-treatment (t3), and
3 months post-treatment (t4). Patients were invited to the Jellinek treatment center for all
assessments, except for the shorter 3-month follow-up, which was administered via telephone. If
a patient was unable to come to the Jellinek for a face-to-face assessment, the mid-treatment or
post-treatment assessments were also administered by telephone (N = 7 at post-treatment). There
was no financial compensation for research and treatment participation.
The study was approved by the ethics committee of the University of Amsterdam (Faculty
of Social and Behavioral Sciences; reference number 2008-KP-342), and submitted to the
Clinical Trials Register, ClinicalTrials.gov (Trial # NCT00763542).
Statistical Methods
All analyses were performed using the IBM Statistical Package for Social Science
(SPSS), version 19.0 for Windows. T tests and ² tests were used to compare both treatment
conditions on sample characteristics and dropout rates. Treatment effects were investigated with
intent to treat (ITT) analyses. Patients were categorized as ITT if they attended at least one
therapy session. Overall missing data patterns showed very low percentages of item non-response
(< 2%), except for one secondary outcome measure concerning craving (5% item non-response).
This justified the use of response function imputation (Van Ginkel, Van der Ark, & Sijtsma,
2007). Figure 1 shows that unit non-response was lower than 21% over all measurements.
Missing data by unit non-response was handled by multiple imputation (MI) (m=5).
Whole scales were imputed using the complete datafile (k= 91) (Graham, 2009). All analyses
were performed on average values derived from the imputed dataset. For the dependent variables
PDS total score and TLFB (days of abstinence) a general linear model (GLM) repeated measures
145_Untitled-2.job145_Proefschrift Debora van Dam.job
145
was performed. Planned repeated contrasts for time were performed for each condition separately
(at mid-treatment, post-treatment, and at 3-month follow-up). Rank-transformation was
performed additionally if variables were not normally distributed (Conover, 2012).
Non-parametric tests were used to examine differences for diagnostic status
exact test, and McNemars from pre- to post-treatment and follow-up. Effect sizes were
calculated for all primary outcome measures.
Results
Treatment effects
Descriptive data for the primary outcome measures are displayed in Tables 3 and 4. All values
are estimated values based on pooled outcomes on the imputed dataset. The outcome measures
for PTSD were PTSD symptom severity (PDS) and PTSD diagnostic status (SCID-I diagnosis).
The outcome measures for SUD were the number of abstinent days (TLFB) and SUD diagnostic
status (SCID-I diagnosis).
PTSD symptom severity. GLM repeated measures analyses on the imputed dataset
revealed a main effect for time, F(3, 34) = 6.37, p = .001,
for condition F(1, 34) = 0.01, p = .921, . No significant interaction effect was found
between condition and time F(3, 34) = 1.92, p = .132, ²= 0.059.
Planned contrast analyses were performed for both treatment groups to assess the decrease
in symptoms from pre- to mid-treatment, from mid- to post-treatment, and from post-treatment to
follow-up. For the TAU + SWT group a significant decrease in PTSD severity was found from
mid-treatment to post-treatment F(1, 19) = 9.31, p = .007, ²= 0.341, but not from pre-
treatment to mid-treatment F(1, 19) = 0.67, p = .424, ²= 0.036, or from post-treatment to
follow-up F(1, 19) = 3.01, p = .100, ²= 0.143. For the TAU group no significant
decreases in PTSD symptom severity were found between the measurement points F’s
0.92, p’s .353,
146_Untitled-2.job146_Proefschrift Debora van Dam.job
14
6
Tab
le 3
. Des
crip
tive
Ana
lyse
s fo
r P
TSD
for
Inte
nt to
Tre
at S
ampl
e (N
= 3
4) (
Est
imat
ed V
alue
s).
Not
e. P
TSD
= P
osttr
aum
atic
str
ess
diso
rder
. TA
U =
Tre
atm
ent a
s us
ual.
SWT
= S
truc
ture
d W
ritin
g T
hera
py. P
DS
= P
osttr
aum
atic
Dia
gnos
tic S
cale
. SC
ID =
Str
uctu
red
Clin
ical
In
terv
iew
of
DSM
IV
axi
s I
diso
rder
s. A
= T
AU
+ S
WT
. B =
TA
U. P
re =
Pre
-tre
atm
ent,
Mid
= M
id-t
reat
men
t, Po
st =
Pos
t-tr
eatm
ent,
Fu
= F
ollo
w-
=
dds
rati
o. C
ontr
ast =
Pla
nned
con
tras
ts. G
LM
= G
ener
al li
near
mod
el.*
p <
.05
**p
< .0
01. t
= tr
end.
ns
= n
ot s
igni
fica
nt.
25 O
R =
incr
ease
of
case
s/ d
ecre
ase
of c
ases
(B
resl
ow &
Day
, 198
0).
26
p =
.06)
.
Var
iabl
e (p
rim
ary
outc
ome
mea
sure
s)
TA
U+
SWT
(A
)
(N =
19)
T
AU
(B
)
(N =
15)
G
LM
pa
rtia
l
²
Con
tras
t
part
ial
²
GL
M
part
ial
²
GL
M
part
ial
²
Pr
e
Mid
Po
st
Fu
Pre
Mid
Po
st
Fu
Tim
e T
ime
1 pr
e-m
id
2 m
id-p
ost
3 po
st-f
u
1 pr
e-m
id
2 m
id-p
ost
3 po
st-f
u
Con
di-
tion
Con
di-
tion
Tim
e *
cond
i-
tion
Tim
e *
cond
i-
tion
PDS
tota
l: M
(SD
) 30
.4 (
9.7)
28
.2
(9.0
)
17.6
(12.
0)
23.5
(14.
8)
28.3
(10.
7)
26.5
(9.8
)
24.3
(9.1
)
21.7
(9.4
)
A+
B
**
0.16
6
1 A
ns
B n
s
2 A
*
B n
s
3 A
ns
B n
s
A 0
.036
B
0.0
37
A 0
.341
B
0.0
40
A 0
.143
B
0.0
62
ns
0.00
0 ns
0.
059
OR
25
Fish
er
SCID
(P
TSD
) n
(%
)
t26
PT
SD
Pa
rtia
l & F
ull-
blow
n
19 (
100)
-
9.8
(51.
8)
- 15
(100
)
- 13
.2
(88.
0)
- A
*
B
0
0
- -0
.390
-
-
Pa
rtia
l PT
SD
10 (
52.6
) -
2.8
(14.
7)
- 3 (2
0.0)
- 2.
4
(16.
0)
- A
*
B
0.1
0.8
- -0
.028
-
-
Fu
ll-bl
own
PTSD
9
(47.
4)
- 7 (3
6.8)
- 12
(80.
0)
- 10
.8
(72.
0)
- A
B
0.7
0.8
- -0
.353
-
-
147_Untitled-2.job147_Proefschrift Debora van Dam.job
14
7
Tab
le 4
. D
escr
ipti
ve A
naly
ses
for
SUD
for
Inte
nt to
Tre
at S
ampl
e (N
= 3
4) (
Est
imat
ed V
alue
s).
Not
e. P
TS
D =
Pos
ttrau
mat
ic s
tres
s di
sord
er. T
AU
= T
reat
men
t as
usua
l. SW
T =
Str
uctu
red
Wri
ting
The
rapy
. PD
S =
Pos
ttrau
mat
ic D
iagn
ostic
Sca
le. S
CID
= S
truc
ture
d C
linic
al
Inte
rvie
w o
f D
SM I
V a
xis
I D
isor
ders
. A =
TA
U +
SW
T. B
= T
AU
. Pre
= P
re-t
reat
men
t, M
id =
Mid
-tre
atm
ent,
Pos
t = P
ost-
trea
tmen
t, F
u =
Fol
low
-up.
McN
OR
= O
dds
rati
o. C
ontr
ast =
Pla
nned
con
tras
ts, *
p <
.05
**p
< .0
01. t
= tr
end.
ns
= n
ot s
igni
fica
nt.
27 O
R =
incr
ease
of
case
s/ d
ecre
ase
of c
ases
(B
resl
ow &
Day
, 198
0).
28 p
= .0
6
Var
iabl
e (p
rim
ary
outc
ome
mea
sure
s)
TA
U+
SWT
(A
)
(N =
19)
TA
U (
B)
(N =
15)
GL
M
part
ial
²
Con
tras
t
part
ial
²
GL
M
part
ial
²
GL
M
part
ial
²
Pr
e
Post
Fu
Pre
Post
Fu
Tim
e T
ime
1 pr
e-po
st
2 po
st-f
u
1 pr
e-po
st
2 po
st-f
u
Con
ditio
n C
ondi
tion
Tim
e *
cond
i-
tion
Tim
e *
cond
i-
tion
TL
FB M
(SD
)
Num
ber
of a
bstin
ent d
ays
19.9
(29
.3)
76.8
(15
.5)
61.0
(30.
8)
20.1
(25
.4)
66.0
(30
.3)
58.6
(38.
4)
A+
B**
0.57
0
1 A
* B
*
2 A
* B
ns
A 0
.784
B 0
.668
A 0
.292
B
0.0
52
ns
0.01
1 ns
0.
15
SCID
n (
%)
Subs
tanc
e us
e di
sord
ers
O
R27
Fi
sher
- -
P
rim
ary
SUD
(
not i
n re
mis
sion
)
18 (
47.0
) 2.
4 (1
2.64
) -
12 (
80.0
) 4.
8 (3
2.0)
-
A**
B*
0 0.1
ns
-0.2
44
- -
SU
D to
tal
(
not i
n r
emis
sion
)
18 (
47.0
) 2.
6 (1
3.7)
-
12 (
80.0
) 5.
8 (6
8.7)
-
A**
B t28
0 0.2
ns
-0.2
93
- -
(Sin
gle
SUD
dia
gnos
is,
not
in r
emis
sion
)
9 (4
7.4)
2.
6 (1
3.7)
-
6 (4
0.0)
5.
8 (6
8.7)
-
- -
- -
- -
(2 S
UD
dia
gnos
es
not
in r
emis
sion
)
6 (3
1.6)
0
(0)
- 3
(20.
0)
0 (0
) -
- -
- -
- -
not
in r
emis
sion
)
3 (1
5.8)
0
(0)
- 3
(20.
0)
0 (0
) -
- -
- -
- -
148_Untitled-2.job148_Proefschrift Debora van Dam.job
148
PTSD diagnostic status. For both conditions, differences for PTSD diagnostic status
were investigated with McNemars ificant increase was found for the number
of remitted cases (partial and full- N =
19) = 8.20, p = .004. More specifically, there was a significant decrease for partial PTSD,
N = 19) =5.07, p = .024, but not for full- N =
19) = 0.17, p
(1, N = 15 p’s > .317. To investigate differences for PTSD diagnoses between TAU +
SWT and TAU at post- -treatment results
indicated a trend for between-group differences in PTSD diagnostic status (p = .06). After
TAU+ SWT less patients were diagnosed with PTSD than after TAU.
Abstinence. Overall abstinence from alcohol and drugs was calculated from
main effect for time F(2, 34) = 42.38, p < .001, partial indicating an increase for
the number of drug and alcohol free days from pre-treatment to follow-up. Neither a main
effect for condition F(2, 34) = 0.35, p = .557, nor a Time x Condition
interaction effect was found, F(2, 34) = 0.48, p = .620, . Outcomes were
similar after rank-transformation (Conover, 2012).
For each treatment condition, planned contrast analyses were performed to assess
changes in abstinence from pre- to post-treatment, and from post-treatment to follow-up. For
TAU + SWT, significant increases in abstinence were found from pre-treatment to post-
treatment F(1, 19) = 65.21, p < .001, , and significant decreases in abstinence
from post-treatment to follow-up F(1, 19) = 7.42, p = .014, . The TAU group
only revealed an increase for abstinence from pre-treatment to post-treatment F(1, 15) =
28.14, p < .001,
from post-treatment to follow-up F(1, 15) = 0.77, p = .396, .
SUD diagnostic status. To compare SUD diagnostic status from pre- to post-
treatment, McNemars
TAU + SWT all showed significant decreases for SUD diagnostic status. (1, N
= 19 , p < .001). For TAU, the number of Primary SUD diagnoses decreased
significantly from pre- to post-treatment, N = 15) = 4.7, p = .03, and a trend
was noticed for the decrease of total number of SUD diagnoses, M N = 15) =
3.4, p = .06. Post-treatment differences for SUD diagnostic status between TAU + SWT and
between both groups (p’s > .23).
149_Untitled-2.job149_Proefschrift Debora van Dam.job
149
Discussion
The aim of this RCT was to investigate the effectiveness of adding treatment for
concurrent PTSD on to an intensive SUD treatment program. It was expected that the
combination of these two evidence-based treatments would lead to improved prognoses.
According to the first hypothesis, a reduction of SUD and PTSD symptoms was
expected in both conditions. This expectation was generally confirmed by findings for SUD.
Overall, there was a significant decrease of SUD symptoms from pre-treatment to follow-up.
Planned contrasts showed an increase in abstinence for both TAU and TAU + SWT during
treatment, but also some decrease of improvements from post-treatment to follow-up for TAU
+ SWT. In addition, both groups showed a significant remission for the primary SUD
diagnosis. Furthermore, a significant reduction for the total number of SUD diagnoses was
found in the TAU + SWT group, and a trend was found for TAU. In sum, both conditions
were effective in reducing SUD, which was to be expected as SUD was targeted in the same
way in both groups. Importantly, the current results also show that it appears safe to provide
trauma-focused treatment for PTSD in combination with SUD treatment, which is in contrast
to frequent clinical belief.
Based on the idea that SUD and PTSD are mutually maintained by a vicious cycle, it
was expected that successful SUD treatment should also reduce symptom levels of PTSD.
Hypothesis 1 therefore also predicted that PTSD should significantly be reduced in both
treatment conditions. At the same time, Hypothesis 2 predicted that PTSD should improve
more after combination treatment compared to TAU. Analyses testing these two hypotheses
provided somewhat mixed results. Symptom levels of PTSD significantly decreased over time
in the overall sample, which can be interpreted as support for Hypothesis 1. In contrast to
Hypothesis 2, no significant interaction between time and condition emerged, i.e. we did not
find clear-cut evidence for a superiority of TAU + SWT over TAU. However, there was
indirect evidence suggesting that the addition of SWT to TAU may be beneficial. First,
planned contrasts showed only a significant reduction of PTSD symptoms during SWT for the
TAU + SWT group, but no significant reductions for PTSD during or after TAU. This
indicates that the overall decrease of PTSD in both groups could mainly be attributed to the
results of the SWT+ TAU condition. Furthermore, PTSD diagnoses decreased in both
conditions, but this reduction was only significant in the TAU + SWT condition. Finally, at
post-treatment a trend was found for between-group differences for PTSD diagnostic status,
150_Untitled-2.job150_Proefschrift Debora van Dam.job
150
indicating that fewer patients were diagnosed with PTSD (partial or full-blown) after TAU +
SWT than after TAU.
Thirdly, we expected that TAU + SWT would be more effective in reducing symptoms
of SUD than TAU alone. This prediction was based on the self-medication hypothesis, which
suggests that successful PTSD treatment may lead to more sustainable abstinence as the need
to self-medicate is reduced. This hypothesis was not supported by any type of analysis.
In sum, both treatments were found to be equally effective in treating SUD. We found
preliminary evidence suggesting that TAU + SWT may be more effective in treating PTSD
symptoms than TAU, although this was not supported by the crucial Time x Condition
interaction on PTSD symptom severities, but only by a number of indirect findings. The fact
that the interaction effect was not significant may be due to different factors. First, differences
between both groups were difficult to detect, due to the small sample size and therefore
reduced power. Another possibility is that the dose of SWT treatment was too low to realize
significant improvements for PTSD symptoms. Interestingly, the reduction of diagnostic
status in the combination condition was only significant for the partial PTSD group but not for
patients with full-blown PTSD. This could also be interpreted as support for the idea that
trauma survivors with SUD and high symptom levels of PTSD may need a higher dose of
treatment. In any case, a replication of the findings in a larger sample is necessary before any
firm conclusions can be drawn.
In an other study, we evaluated integrated trauma-focused SWT for PTSD and CBT
for SUD within a larger sample of outpatients (N = 96) (Van Dam et al., submitted). These
outcomes showed that PTSD and SUD symptoms were treated effectively in both conditions.
In addition, completer analyses favored trauma-focused integrated treatment above CBT for
SUD in reducing PTSD symptom severity. Apart from sample size, there were other
important differences in sample characteristics between the present and the previous study.
Most importantly, the current patient sample was more severe. This was mirrored by the need
for a more intensive treatment program for SUD complaints, but also in less mean abstinent
days at baseline (20 versus 34) and slightly higher mean baseline scores for PTSD (30 versus
27). Sample characteristics for both studies showed that the current sample comprised
relatively more men, more patients with a lower education, more patients without a
relationship, and more patients without work. Although the present patient group was more
severe, overall dropout percentages were lower (overall: 38%; TAU + SWT: 47%; TAU:
27%), compared to the previous study (overall: 46 %; TAU + SWT: 51%; TAU: 40%), but
also compared to other findings in this area of research (Van Dam et al., 2012). Importantly,
151_Untitled-2.job151_Proefschrift Debora van Dam.job
151
dropout percentages did not differ significantly between conditions, although a study
comprising a larger sample size and therefore higher statistical power is necessary to provide
conclusive evidence on this issue. Although the dropout rates observed in the current study
are comparable to earlier research in this field, they are nevertheless far from satisfactory.
Future research should aim at improving the acceptability of combined treatments for PTSD
and SUD. Notably, in the current study most patients dropped out before SWT started (33%),
or during the first phase of self-confrontation of the SWT treatment (56%). Only one patient
ended treatment just after the self-confrontation phase (11%). This suggests that patients were
inclined to shudder from, or terminate during, the assignments comprising trauma-focused
exposure. Future studies should explore whether a longer phase of preparation for trauma-
focused treatment may increase the acceptability of this type of intervention.
The lack of significant between-group differences for SUD in the current study is
consistent with previous findings in less severe patients (McGovern et al., 2011; Mills et al.,
2012; Van Dam et al., submitted; Van Dam et al., 2012). There may be several explanations
for this phenomenon (Van Dam et al., submitted). First, SUD treatment was equal in both
conditions, which may have been so effective that group differences were leveled out. In
addition, long-term follow-up may be needed to prove differences between the two conditions
on SUD outcomes; PTSD improvements have a better chance to positively influence SUD
symptoms after a longer period of time (McGovern et al., 2011; Van Dam et al., submitted). A
1-year follow-up assessment is currently underway.
Besides the small sample size, a number of additional limitations are noteworthy. First
the current sample comprised a mixed group of inpatients and daycare patients. However, the
setting for inpatients and daycare patients was very similar. For example, both groups
attended their treatment at the same location, the content of both programs was alike, and
most important, the group intervention for SUD was the same in both conditions. Second,
patients suffering from BPD were excluded from the study due to ethical reasons. It is
therefore not clear whether the current results also apply to this subgroup of patients. Third,
whereas diagnoses of PTSD and SUD were established using structured clinical interviews at
pre- and post-treatment, the 3-month follow-up assessment exclusively comprised self-report
measures, which can be regarded as a limitation of the current study. A 1-year follow-up
assessment including structured clinical interviews to assess diagnostic criteria is currently
underway and will provide more conclusive evidence on the long-term effects of the two
treatment conditions.
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An important strength of this RCT is its specific focus on external validity. The
intervention was studied in a routine clinical setting under everyday circumstances. This
means that results can easily be generalized to regular clinical practice. Another strength was
that all patients were offered the same type of SUD treatment, facilitating interpretations
about the added value of TAU + SWT compared to TAU.
Although the small sample size, and the indirect nature of findings supporting a
superiority of TAU + SWT, prevent us from drawing firm conclusions, the outcomes of this
study are encouraging enough to continue investigating trauma-focused treatment for patients
with concurrent PTSD and SUD. Trauma-focused PTSD treatment preliminary appears more
effective in decreasing PTSD and SUD symptoms than SUD treatment alone, without
jeopardizing patient (Mills et al., 2012; Van Dam et al.,
submitted), also if it concerns a more severe SUD patient group.
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CChapter 7
General discussion
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General discussion
The intention of this final chapter is to draw conclusions regarding the screening and
treatment of posttraumatic stress disorder (PTSD) within substance abuse treatment centers.
Outcomes of the four studies and the systematic review will be integrated with other research
findings in this area, and will be placed into a broader perspective. Subsequently,
recommendations for clinical practice and further research will be made. Finally, some critical
notes and reflections will be considered.
Screening for PTSD among SUD patients
The purpose of the research presented in this thesis was to contribute to the
improvement of treatment for patients with concurrent PTSD and substance use disorder
(SUD). A necessary first step for attaining that goal was the validation of a screener that can
be used in clinical practice to detect patients with this comorbidity. In two studies within a
substance abuse treatment center, the extended version of the Primary Care posttraumatic
stress disorder screening questionnaire (PC-PTSD) (Chapter 2), and its derivative the Jellinek-
PTSD screening questionnaire (J-PTSD) (Chapter 3), were examined and cross-validated. The
rationale for choosing the PC-PTSD as a starting point for our research was grounded in the
proven quality of this screener for SUD patients in a VA setting (Kimerling, Trafton, &
Nguyen, 2006). In addition, the easy administration and scoring rules of this screener were an
important factor in that decision. Research findings within the SUD patient samples of the
current thesis indicated a high sensitivity (.86) and a moderate specificity (.63) for the PC-
PTSD, and a high sensitivity (.87) and specificity (.75) for the J-PTSD. For both screeners,
the optimal cut-off was 2, which is lower than the original cut-off of 3 of the PC-PTSD
(Kimerling et al., 2006). This was possibly due to the fact that our studies comprised civilian
SUD patients instead of military SUD patients, as a lower cutoff for PTSD questionnaires has
been found more often for civilians compared to military patients (see Chapter 2).
Until now, nine studies have been performed investigating the psychometric qualities
of PTSD screeners within SUD samples, including the two studies of the current thesis (see
Table 1). Compared to other screeners validated among SUD patients, the J-PTSD has similar
or superior qualities, while taking little time and effort to administer and score. The J-PTSD
has been investigated in routine clinical practice, which increases the generalizability of the
results (Calder, Phillips, & Tybout, 1982). However, a possible threat to this generalizability
may be the lower incidence of full-blown and partial PTSD in our study samples compared to
161_Untitled-2.job161_Proefschrift Debora van Dam.job
16
1
Tab
le 1
. PT
SD S
cree
ning
Que
stio
nnai
res
Inve
stig
ated
wit
hin
A S
ampl
e of
SU
D P
atie
nts.
Que
stio
nnai
re
It
Stu
dy
PTSD
C
rite
rion
Se
Sp
e PP
P N
PP
N
Sam
ple
MPS
S-R
(Fa
lset
ti, R
esni
ck, R
esic
k, &
K
ilpat
rick
, 199
3),
17
Cof
fey,
Dan
sky,
Fal
sett
i, Sa
ladi
n, &
Bra
dy, 1
998
NW
S P
TSD
.8
9 .6
5 .6
0 .9
1 11
8 Pa
tien
ts a
dmitt
ed to
an
inpa
tien
t or
outp
atie
nt S
ubst
ance
Dep
ende
ncy
trea
tmen
t pro
gram
PC-P
TSD
(Pr
ins
et a
l., 2
003)
4
Kim
erlin
g et
al.,
200
6 SC
ID
.91
.8
0 .6
9 .9
5 97
Pa
tien
ts f
rom
sub
stan
ce u
se tr
eatm
ent c
lini
cs a
t a V
eter
an A
ffai
rs (
VA
) m
edic
al c
ente
r
PC-P
TSD
(Pr
ins
et a
l., 2
003)
4 V
an D
am, E
hrin
g, V
edel
, &
Em
mel
kam
p, 2
010
SCID
.8
6 .5
7 .2
6 .9
6 14
2 Pa
tien
ts a
dmitt
ed to
an
inpa
tien
t or
outp
atie
nt S
ubst
ance
Dep
ende
ncy
trea
tmen
t pro
gram
J-PT
SD (
Van
Dam
, Ehr
ing,
Ved
el, &
E
mm
elka
mp,
201
3)
4 V
an D
am e
t al,
2013
SC
ID
.87
.75
.41
.97
92
Pati
ents
adm
itted
to a
n in
pati
ent o
r ou
tpat
ient
Sub
stan
ce D
epen
denc
y tr
eatm
ent p
rogr
am
PC
L-C
(W
eath
ers,
Lit
z, H
uska
, &
Kea
ne, 1
994)
17
Har
ring
ton
& N
ewm
an, 2
007
CA
PS
.76
.79
.70
.83
44
Wom
en in
res
iden
tial s
ubst
ance
use
trea
tmen
t
PI (
Ham
mar
berg
, 199
2)
26
Har
ring
ton
& N
ewm
an, 2
007
CA
PS
.76
.79
.70
.83
44
Wom
en in
res
iden
tial s
ubst
ance
use
trea
tmen
t
IES
(Wei
ss &
Mar
mar
, 199
7)
15
Ras
h, C
offe
y, B
asch
nage
l, D
robe
s, &
Sal
adin
, 200
8
CA
PS
.92
.57
.74
.83
124
Su
bsta
nce
Dep
ende
nt p
atie
nts
(alc
ohol
and
/ or
coca
ine)
PDS
(Foa
, Cas
hman
, Jay
cox,
& P
erry
, 19
97)
17
Pow
ers,
Gill
ihan
, Ros
enfi
eld,
Je
rud,
& F
oa, 2
012
SCID
.8
7 .6
3 .5
5 .9
0 16
7 Pa
tien
ts w
ho w
ere
diag
nose
d w
ith
Alc
ohol
Dep
ende
nce
PSS-
I (F
oa, R
iggs
, Dan
cu, &
R
othb
aum
, 199
3)
17
Pow
ers
et a
l., 2
012
SCID
.8
6 .9
0 .8
1 .9
3 16
7 Pa
tien
ts w
ho w
ere
diag
nose
d w
ith
Alc
ohol
Dep
ende
nce
MIN
Iplu
s (P
TSD
) (S
heeh
an e
t al.,
19
98)
19
Kok
et a
l., 2
012
CA
PS
.58
.91
n/r
n/r
197
Pa
tien
ts a
dmitt
ed to
inpa
tient
add
icti
on tr
eatm
ent d
iagn
osed
wit
h cu
rren
t su
bsta
nce
use
diso
rder
(A
lcoh
ol o
r D
rug
Abu
se o
r D
epen
denc
e)
SR
IP (
Hov
ens
et a
l., 1
994)
22
K
ok e
t al.,
201
2 C
APS
.8
0 .7
3 .5
1 .9
1 19
7
Pati
ents
adm
itted
to in
patie
nt a
ddic
tion
trea
tmen
t dia
gnos
ed w
ith
curr
ent
subs
tanc
e us
e di
sord
er (
Alc
ohol
or
Dru
g A
buse
or
Dep
ende
nce)
Not
e. P
TSD
= P
osttr
aum
atic
str
ess
diso
rder
. SU
D =
Sub
stan
ce u
se d
isor
der.
SC
ID-I
= S
truc
ture
d C
linic
al I
nter
view
for
DSM
-IV
axi
s I
Dis
orde
rs. I
t = I
tem
s. S
e =
Sen
sitiv
iy. S
pe =
Spe
cifi
city
; P
PP
= P
osit
ive
pred
icti
ve p
ower
. NP
P =
Neg
ativ
e pr
edic
tive
pow
er. C
AP
S =
Clin
icia
n-A
dmin
iste
red
PT
SD
Sca
le. I
ES
= I
mpa
ct o
f E
vent
Sca
le. M
PSS
-R =
Mod
ifie
d ve
rsio
n of
the
PT
SD
Sym
ptom
Sca
le-S
elf-
Rep
ort.
PC
L-C
= P
TSD
Che
cklis
t Civ
ilian
ver
sion
. PI
= P
enn
Inve
ntor
y. P
C-P
TS
D =
Pri
mar
y C
are
post
trau
mat
ic s
tres
s di
sord
er s
cree
n. P
DS
= P
osttr
aum
atic
Dia
gnos
tic
Scal
e. P
SS-I
= P
TSD
Sym
ptom
Sca
le-i
nter
view
. MIN
Iplu
s =
Min
i Int
erna
tiona
l Neu
rops
ychi
atri
c In
terv
iew
plu
s. S
RIP
= S
elf-
Rep
ort I
nven
tory
for
PT
SD
. n/r
= n
ot r
epor
ted.
162_Untitled-2.job162_Proefschrift Debora van Dam.job
162
other studies among SUD patients (Harrington & Newman, 2007; Kimerling et al., 2006).
In Chapters 2 and 3, possible explanations for this discrepancy are discussed, such as
differences in sample characteristics (high educational level, relatively more men than
women, and no chronic care patients in our samples), procedural differences (blinded
interviewers, and the use of the SCID-I instead of the CAPS in our samples) and differences
in mental health care systems across different countries (relatively easy access to PTSD
treatment in the Netherlands, which may facilitate early PTSD detection and treatment, and
prevent secondary substance abuse).
The active screening for PTSD among SUD patients can improve the detection rate of
PTSD by four times (Kimerling et al., 2006). Therefore, the use of PTSD screening
questionnaires may contribute in a substantial way to improving the recognition and treatment
of comorbid PTSD and SUD. Both screeners investigated in this thesis were administered
before the beginning of treatment. Importantly, this timing corresponds with the practical use
of PTSD screeners in everyday practice, as their ultimate purpose is to facilitate proper
treatment allocation. However, as a consequence, most patients in our studies had not
achieved abstinence yet from alcohol or drugs when filling out the screener.
This poses the question whether the outcomes for both screeners can be generalized to
abstinent SUD populations. It would therefore be informative to investigate the psychometric
qualities of the PC-PTSD and the J-PTSD again within a group of abstinent SUD patients.
Another recommendation for future research, also described in Chapters 2 and 3, is to conduct
the diagnostic assessment of PTSD after 4 weeks of abstinence to exclude the possibility that
the reporting of PTSD symptoms during the diagnostic interview was influenced by recent
substance use.
Combined treatment for concurrent PTSD and SUD
Three chapters focused on combined treatments for concurrent PTSD and SUD, and
on trauma-focused interventions in particular. In Chapter 4, a systematic review was
presented. Seventeen relevant articles were discussed evaluating ten treatment protocols for
concurrent PTSD and SUD. All papers had been published before January 2011. Overall,
symptom reductions were found for PTSD and SUD after combined treatment, although most
results were not superior to regular SUD treatments. Preliminary findings suggested that
trauma-focused treatment could lead to better treatment outcomes. This strengthened our view
163_Untitled-2.job163_Proefschrift Debora van Dam.job
163
that the guidelines prescribing trauma-focused treatment for single diagnose PTSD (Bisson et
al., 2007) were also applicable to patients with concurrent PSTD and SUD.
In Chapters 5 and 6, two randomized controlled trials (RCTs) were presented
evaluating the effectiveness of trauma-focused treatment combined with SUD treatment-as-
usual. The trauma-focused intervention was Structured Writing Therapy (SWT) that
incorporates specific writing assignments to reprocess traumatic events (Lange, Van de Ven,
Schrieken, & Emmelkamp, 2001; Van Emmerik, Kamphuis, & Emmelkamp, 2008). An
important assumption for both RCTs was that substance use may interfere with the extinction
of trauma (Stewart & Conrod, 2003). Therefore, in both studies a four week period of
abstinence was strived for before SWT started. All patients received psycho-education about
the vicious circle of PTSD and SUD at the beginning of treatment. In this way, insight was
given about the functional relationship of both disorders, preparing patients for possible
exacerbations of PTSD in the first period of abstinence, and motivating them to stay in SUD
treatment, as the functional relationship predicts that PTSD symptoms may improve after
continued abstinence. Also, patients were told that abstinence was an important condition for
PTSD treatment to be successful.
For every subject, treatment outcomes were monitored on four separate time points; at
pre-, mid- and post-treatment, and at 3-month follow-up. The first measurement was
performed before treatment, including psycho-education, had started. Most patients were still
using substances at that time. The second measurement was timed after the fifth session, after
patients had accomplished abstinence for approximately 4 weeks, and just before SWT started
in the experimental group. In this way, the influence of psycho-education and maintained
abstinence on PTSD symptoms could be narrowed down more specifically. The third
measurement was at post-treatment, estimating the direct effects of the concurrent treatment
of PTSD and SUD. The fourth measurement was performed three months after the end of
treatment, to study long term treatment effects. A 12-month follow-up was carried out as a
fifth measurement. However, the outcomes are not included in the present thesis as these
results are still underway. The treatment results of both clinical trials are briefly discussed
below.
In Chapter 5, the effectiveness of a combined treatment for PTSD and SUD was
investigated, integrating the SWT protocol with cognitive behavioral treatment (CBT) for
SUD (CBT/SUD + SWT). This intervention was compared to CBT for SUD alone
(CBT/SUD). The study included outpatients of a substance abuse treatment center (N = 96).
164_Untitled-2.job164_Proefschrift Debora van Dam.job
164
ITT analyses as well as completer analyses were performed. In general, both treatments were
effective in decreasing PTSD and SUD. In the completer sample, CBT/SUD + SWT showed
superior results for PTSD compared to CBT/SUD. These outcomes suggest that patients need
to receive a minimal dose of trauma-focused therapy, before they achieve better treatment
effects for PTSD in the combined treatment compared to CBT/SUD only. Therefore, a
recommendation for clinical practice would be to inform patients about the necessity of
treatment completion to benefit fully from the CBT/SUD + SWT intervention. Finally, no
differences were found between the interventions CBT/SUD + SWT and CBT/SUD for the
improvements on SUD; both treatments had the same positive effect. This is at odds with our
presumption, following from the self-medication hypothesis and earlier research findings, that
CBT/SUD + SWT would lead to better results for SUD compared to CBT/SUD alone. One
possible explanation is that the CBT/SUD intervention in both treatment groups had such
large positive effects on SUD, that SUD outcomes were equalized. Otherwise, the CBT/SUD
intervention already realized improvements on PTSD symptoms. Perhaps these were
sufficient to decrease the need for self-medication in the CBT/SUD group also. Finally, it is
possible that group differences for SUD will be noticed only after a longer term follow-up
period than three months, as the expected difference for abstinence is assumed to be an
indirect effect following from a decline in PTSD symptoms. Although dropout percentages
were high (46%), findings contradicted the general concern that trauma-focused therapy leads
to higher dropout percentages as dropout did not differ between the two treatment conditions.
Chapter 6 consisted of an RCT including thirty-four severe SUD patients. In this study,
SWT was added on to treatment as usual (TAU), an intensive SUD treatment format (clinical
or daycare). The experimental condition was TAU + SWT, and the control condition was
TAU. Due to the small sample size, ITT analyses were performed only. Similar to in the
outpatient study, both treatment groups showed a reduction of SUD symptoms. However, the
results for PTSD complaints were different from the outpatient study, as improvements for
PTSD were not equal for both treatment groups over time, and were only found for TAU +
SWT. Although this finding may suggest superiority of TAU + SWT in decreasing PTSD
severity, data-analyses did not confirm between group differences statistically. Still, these first
results are hopeful, especially in the light of the small and therefore underpowered sample
size, and considering the severity of the patient group. Also, this treatment showed a relatively
low dropout percentage (38%), and no differences in dropout rates were found between both
groups.
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Comparing the results of the two RCTs investigating trauma-focused PTSD treatment
for patients with concurrent PTSD and SUD, the outcomes of the outpatient study
investigating the integrated protocol CBT/SUD + SWT were more convincing than the RCT
among severe SUD patients investigating the combined protocols of TAU + SWT. As
discussed in Chapter 6, this may be due to differences in sample size and patients
characteristics. It may also reflect an important difference of the applied PTSD intervention.
In the outpatient group, most patients performed their homework assignments, including
trauma-focused exposure, at home. In the daycare or clinical care group, on the other hand,
most patients performed their homework assignments within the clinic. After treatment, the
outpatients stayed in the context of the trauma-focused exposure, but the daycare or clinical
care group experienced a context change. This may have been a disadvantage for the latter
group as the extinction of fear is presumed to be context dependent (Bouton, 2002; Effting &
Kindt, 2007; Herry et al., 2010). It is plausible that the possible extinction of PTSD
complaints within the clinic did not pertain in the home environment, and it may therefore be
recommendable to repeat trauma-focused exposure by patients at home. An important
consideration for the implementation in real-life clinical practice may be to repeat trauma-
focused interventions within the home environment in order to facilitate situation specific
extinction.
Nonetheless, results of both studies are encouraging. First, they provide some evidence
indicating that concurrent trauma-focused treatment for PTSD and SUD may be superior to
SUD treatment alone, at least if a sufficient dose of PTSD treatment is received. However, the
outcomes are not clear-cut, and more research is needed to draw firmer conclusions. In this
context, it would be informative to investigate the sustainability of treatment effects on the
longer-term (e.g., 12 months). Second, the outcomes make a valuable contribution to the
scientific discourse about trauma-focused exposure for patients with concurrent PTSD and
SUD (Brady, Dansky, Back, Foa, & Carroll, 2001; Foa & Rothbaum, 1998; Henslee &
Coffey, 2010; Van Minnen, Harned, Zoellner, & Mills, 2012; Van Minnen, Hendriks, & Olff,
2010). For the past decades, this area of research was mostly predominated by the thought that
concurrent PTSD and SUD was a contra-indication for trauma-focused exposure. Concerns
were that trauma-focused exposure would lead to symptom exacerbation and adverse events
(Hien, Cohen, Miele, Litt, & Capstick, 2004). The results of both RCTs seem to disprove this
concern. No indications were found for more dropout or symptom worsening after trauma-
focused exposure. Therefore both studies suggest that it is safe to apply trauma-focused
166_Untitled-2.job166_Proefschrift Debora van Dam.job
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exposure, the gold standard treatment for single diagnosis PTSD, to patients with concurrent
PTSD and SUD.
Notably, these outcomes are in line with those of a recently published RCT,
investigating prolonged exposure during SUD treatment for patients with comorbid PTSD an
SUD, indicating improvement in PTSD symptoms without an increase of substance
dependence (Mills et al., 2012). Interestingly, like the study of Mills et al. (2012), our results
showed that SUD treatment alone, in some cases, can lead to a reduction of PTSD symptoms.
This finding may be explained in several ways. Firstly, the hypothesized reciprocal
relationship between PTSD and SUD (Stewart & Conrod, 2003) could be a plausible
explanation. As described in Chapter 1, PTSD symptoms may lead to substance abuse in an
attempt to self-medicate. Inversely, substance abuse may sustain or worsen the symptoms of
PTSD by increasing the chance of repeated trauma, by triggering PTSD symptoms by the
physical sensations of withdrawal (Stewart & Conrod, 2003; Wald & Taylor, 2008), by
interfering with trauma extinction (Stewart & Conrod, 2003), and by maintaining emotional
numbing in PTSD (Stewart, 1996). Consequently, achieving and maintaining abstinence
, would terminate withdrawal to trigger PTSD symptoms,
would improve the conditions for trauma extinction, or would improve symptoms of
avoidance caused by substance use. However, this assumption was also the basis of the
psycho-education that all participants received. This specific information about the possible
perception accordingly. A third explanation would be that symptoms related to substance
abuse (e.g. difficulty concentrating), were falsely interpreted as PTSD symptoms. However,
we aimed to rule out this contamination by the thorough training of research interviewers,
instructing them to ask participants explicitly whether the reported symptoms were related to
substance use or traumatic event(s). Further research is needed to shed more light on the
functional relationship between PTSD and SUD. It seems also warranted to explore the
ces used, order
of PTSD and SUD onset, or the sensitivity for anxiety (Wald & Taylor, 2008). There may be
different pathways for specific subgroups of patients.
Internal versus external validity in clinical research
An important focus of the present thesis was the applicability of research findings to
real-clinical practice. In clinical research, the concept of external validity addresses the
167_Untitled-2.job167_Proefschrift Debora van Dam.job
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generalizability of research findings to relevant real-life patients and real-life practice (Calder
et al., 1982). The term internal validity refers to the extent that research findings are unbiased
and can actually be ascribed to the studied intervention. Studies with a high level of external
validity investigate an intervention under real-life circumstances. These trials are referred to
as effectiveness trials. Studies with a high level of internal validity investigate an intervention
under the ideal circumstances, and are referred to as efficacy trials (Steckler & McLeroy,
2008). In the past, research often focused on internal validity to the detriment of external
validity. This has troubled the transfer of scientific knowledge into clinical practice (Steckler
& McLeroy, 2008). Increasingly, researchers acknowledge the need to pay more attention to
external validity, and it is recognized as an important criterion for clinicians to determine the
practical applicability of clinical research (Rothwell, 2005; Stewart & Chambless, 2009). It
has been suggested that effectiveness and efficacy are opposites on the same continuum, and
that most studies can be placed somewhere in the middle of this line (Kraemer, 2000). In our
thesis our main focus was the generalizability to clinical practice, and therefore, in our
opinion, the studies tend to be more on the effectiveness side of the continuum. The research
setting, and therapists were representative for clinical practice, and we used as little exclusion
criteria as ethically possible. Still, we have tried to reach equilibrium between real-life
applicability and study rigor.
Strengths of the current thesis
The current thesis has several important strengths. The research procedures were
respectively double-blind and blind in the studies investigating the diagnostic qualities of the
PC-PTSD and the J-PTSD. In the PC-PTSD study, the patients were not informed that PTSD
was the topic of research, and in both screener studies the interviewers were blind for the
answers a patient had filled out on the screener.
In both clinical trials, patients were randomized to research conditions. Generally, all
therapists involved in the studies were supervised on a regular basis by members of the
research staff, to maximize adherence to study procedures and treatment protocols. Also,
patients participating in the study received a similar SUD treatment program, and were not
permitted to have alternative psychological care during the time from pre-treatment up to
follow-up. This requirement enabled us to investigate the specific influence of the
experimental treatment SWT. Although standardization of the control treatment appears to be
an important condition for evaluating treatment effectiveness, the criterion of uniformity was
168_Untitled-2.job168_Proefschrift Debora van Dam.job
168
not satisfied in several RCTs in this research area (Hien et al., 2009; Killeen et al., 2008; Mills
et al., 2012; Najavits, Gallop, & Weiss, 2006).
Furthermore the research procedures were implemented into routine clinical care,
using regular treatment staff. For example, the PTSD screener was offered to patients during
the intake phase, while most of them where still using alcohol and/or drugs. The
administration of the screener during the intake phase is in accordance with real clinical
practice, as PTSD screening ultimately serves to facilitate proper treatment allocation. In
addition, all patients were recruited within the substance abuse center. Compared to studies
using advertising to recruit patients (e.g. Hien et al., 2009), the generalizability of our results
to clinical samples is assumingly better (Winhusen, Winstanley, Somoza, & Brigham, 2012).
Finally, in order to give more insight into the practical applicability of findings, the eligibility
and participation of subjects was clearly described, and explicated in flow-charts.
Critical notes and reflections
In the following, several limitations of the conducted studies will be discussed. First of
all, in both RCTs all study participants received psycho-education (10 to 15 minutes) about
the vicious circle of PTSD and SUD, while this type of psycho-education is not given to
patients in normal practice. For that reason, one could question whether the control
intervention was really TAU. As a consequence, it remains unclear what the relative effect of
SWT is compared to TAU without psycho-education, and it is also uncertain to what extent
the positive treatment effects seen in both groups were accountable to psycho-education.
However, this concession in research procedures was made on ethical grounds. It seemed
unethical to ask patients thoroughly about traumatic events from the past and PTSD
complaints, without giving them any perspective on the possible relationship of PTSD and
SUD and the expected patterns of progress, especially since we assumed that this information
would help patients through the first difficult period of achieving abstinence. However, it is
important to note that the possible positive influence of psycho-education is speculative. As
far as we know, no research data are available investigating specifically the effectiveness of
brief psycho-educational interventions for concurrent PTSD and SUD.
A second limitation related to ethical considerations was the absence of a waiting-list
condition, which made it impossible to control for potential symptom improvements caused
by natural recovery. Considering the severity of this patient group, it seemed unethical to
delay treatment for research purposes.
169_Untitled-2.job169_Proefschrift Debora van Dam.job
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A limitation in both treatment studies was the tendency of patients to postpone their
treatment sessions frequently. For that reason, treatments were delayed, despite many efforts
of the participating therapists to make new appointments close to the original date of the
therapy session that was missed. Although unfortunate, the delay of treatment in our studies is
understandable, considering the fact that treatment attendance is often poor for patients with
concurrent PTSD and SUD (Torchalla, Nosen, Rostam, & Allen, 2012). We can only
speculate about the reasons underlying the postponement of sessions. Perhaps it reflects
resistance to treatment demands. However, the postponement of treatment sessions may also
be related to the serious troubles in other areas of life that often exist in this patient group,
which could have drawn the attention away from treatment. The average delay of treatment
for the outpatient RCT was 10 weeks (SD = 6.6). No between group differences for treatment
duration were found t(94) = -1.40, p = .16. Data from the RCT for severe SUD patients
revealed an average treatment duration of 18 weeks (SD = 5.6). A comparison between both
treatment groups showed that the TAU + SWT patients were relatively longer in treatment
than TAU patients t(32) = -2.60, p = .01. Perhaps this dissimilarity can be explained by
different procedures for both groups. As described in Chapter 6, the TAU + SWT group
received additional individual therapy sessions of SWT, while the TAU group only received
the regular treatment program. When TAU + SWT patients postponed their individual
treatment sessions of SWT, they were still allowed to complete SWT. This means that they
could still receive SWT after the day- or inpatient program had finished. For this group, the
timing of the post-treatment measurement was after the last session of SWT. Patients from the
TAU group followed the regular program until they were released, and their post-treatment
measurement was timed on the last treatment day. This timing appeared to be convenient for
the assumption that participation would increase if patients were measured while they were
still within reach of the treatment center. However, this may unintentionally have led to group
differences in treatment duration. Another limitation of both treatment studies was that the
experimental treatments (CBT/SUD + SWT and TAU + SWT) offered a higher dose of
therapeutic contact than the control treatments (CBT/SUD and TAU). This obviously
complicates the interpretation of research findings, as the therapeutic relationship may have
positive effects on its own, regardless of the intervention (Gibbons et al., 2010; Luborsky et
al., 2002). However, it was an inevitable consequence of our main purpose to investigate the
effectiveness of the experimental treatments compared with TAU (Flay, 1986). This implied
that the control treatments could not be different from TAU, and could therefore not be
170_Untitled-2.job170_Proefschrift Debora van Dam.job
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extended or changed to resemble the experimental treatment in the amount of therapeutic
contact.
A final limitation discussed in the context of this thesis is the possibility of a selection
bias for patients who participate in scientific research, which poses a threat to external validity
(Rothwell, 2005). It remains unknown to what extent the findings can be generalized to
eligible patients unwilling to participate in research procedures. This lack of information
could have been prevented if we had incorporated the data of these specific patients into our
analyses in order to compare their characteristics to the included sample. It would be
recommendable for future research to ask eligible non-participants for permission to use
information about their characteristics for further analyses.
Final conclusions and recommendations
Based on the findings of the current thesis, it is recommended to screen for PTSD
within substance abuse treatment centers before treatment has started. In this way, PTSD can
be further assessed, and the allocation to appropriate interventions for PTSD during or after
SUD treatment can be facilitated. The outcomes indicate that the J-PTSD is a valid and
patient-friendly screening tool to be implemented for this purpose in real-life clinical practice.
Regarding the treatment of concurrent PTSD and SUD, evidence, although limited,
seems in favor of a trauma-focused approach. Overall, findings indicate that trauma-focused
interventions can be beneficial to patients with concurrent PTSD and SUD (Coffey,
Stasiewicz, Hughes, & Brimo, 2006; Mills et al., 2012; Van Dam, Ehring, Vedel, &
Emmelkamp, submitted; Van Dam, Vedel, Ehring, & Emmelkamp, 2012), without increasing
the hazard of treatment dropout or relapse in alcohol or drug use (Brady et al., 2001; Van
Dam et al., submitted; Mills et al., 2012). Despite some promising outcomes (McGovern,
Lambert-Harris, Alterman, Xie, & Meier, 2011), empirical support for non-trauma-focused
treatment is thin (Boden et al., 2012; Van Dam et al., 2012). The outcomes of the current
thesis warrant further research to investigate treatment effectiveness of trauma-focused PTSD
treatment within substance abuse treatment centers.
translation of research findings into clinical practice even if the empirical evidence for
trauma-focused treatment would rise (Henslee & Coffey, 2010). The tendency among
therapists to utilize exposure based treatments for PTSD patients with comorbid diagnoses is
relatively low compared to EMDR and supportive counseling (Becker, Zayfert, & Anderson,
171_Untitled-2.job171_Proefschrift Debora van Dam.job
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2004; Van Minnen et al., 2010). As treatment preference appears to be positively related to
the amount of training in a particular intervention, more training in trauma-focused techniques
among SUD therapists may be justified (Van Minnen et al., 2010), as well as advanced
education for therapists about the effectiveness of combined treatment for patients with
concurrent PTSD and SUD.
Based on the results of the current thesis, it is difficult to draw conclusions regarding
the superiority of an integrated treatment approach, where PTSD and SUD treatment are
integrated or combined within the same treatment center, versus a sequential treatment
approach for treating concurrent PTSD and SUD. In both RCTs, treatment completion and
SUD improvements were equal for patients receiving a combined treatment for PTSD and
SUD treatment, compared to patients receiving SUD treatment alone. This implies
theoretically29 that patients who received SUD treatment alone, did have a fair chance to start
PTSD treatment elsewhere after finishing SUD treatment. However, in this context it should
be mentioned again that all patients in our research received psycho-education about the
vicious circle of PTSD and SUD. Although speculative, this may have had a positive
influence on the effectiveness and completion of SUD treatment. Keeping in mind the
vulnerability of this patient group, together with the practical complications in realizing a
well-timed and fluent referral from a substance abuse treatment center to another mental
health organization for PTSD treatment, it appears to be recommendable to offer PTSD
treatment within the same treatment setting as the SUD treatment.
It is clear that research concerning the treatment of concurrent PTSD and SUD is still
in its infancy and that there is still a broad undiscovered area to explore. In fact there are so
many possibilities for further research that a logical ranking of research topics may be useful.
An apparently sound approach is to give priority to the evaluation of treatments that already
have proven their effectiveness for single diagnosis PTSD and SUD. Those are trauma-
focused treatment for PTSD (Bisson et al., 2007; National Collaborating Centre for Mental
Health, 2005; Seidler & Wagner, 2006), and CBT for SUD or twelve-step program for SUD
(Emmelkamp & Vedel, 2006). Surprisingly, to our knowledge no research has been done yet
investigating the effectiveness of EMDR (Shapiro, 2001) for patients with concurrent PTSD
and SUD. This seems an interesting research topic for the near future. Another interesting
29 Procedural demands did not allow patients to follow PTSD treatment until three months after ending SUD treatment.
172_Untitled-2.job172_Proefschrift Debora van Dam.job
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research topic for the long term may be the effectiveness of pharmacological interventions for
concurrent PTSD and SUD. If research among single diagnosis PTSD patients would prove
the effectiveness of these new pharmacological approaches, further research among patients
with concurrent PTSD and SUD would be justified.
For the future it is crucial that different disciplines studying PTSD and SUD treatment
join forces, in order to find the best possible therapy for the challenging group of patients with
concurrent PTSD and SUD.
References
Becker, C. B., Zayfert, C., & Anderson, E. (2004). A survey of psychologists' attitudes
towards and utilization of exposure therapy for PTSD. Behaviour Research and
Therapy, 42, 277-292.
Bisson, J. I., Ehlers, A., Matthews, R., Pilling, S., Richards, D., & Turner, S. (2007).
Psychological treatments for chronic post-traumatic stress disorder: Systematic review
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AAppendix A
THE JELLINEK-PTSD SCREENING QUESTIONNAIRE
PART A
During childhood or adulthood, people can experience threatening, horrible, or shocking
events. This can for example be (the witnessing of) physical intimidation, sexual violence,
sexual abuse, physical violence, a serious accident or a disaster. Have you ever experienced
such a trauma yourself or have you ever witnessed such a traumatic event?
YES (please fill in the list below). NO (end of questionnaire).
In the past month, have you … (circle the right answer)
1. Had bad nightmares about it, or thought about it when you
did not want to? Yes/ no
2. Tried hard not to think about it or gone out of your way to avoid situations
that reminded you of it? Yes/ no
3. Been constantly on guard, watchful, or easily startled? Yes/ no
4 Felt that your future plans or hopes will not come true as a consequence
of the experience? Yes/ no
What kind of event was it? (you can mark several events)
Physical intimidation Rape/ sexual violence
Physical violence/ assault Sexual abuse
Serious accident War
Disaster Other,......................
Score = ___
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SSummary
Roughly, one out of four patients with a substance use disorder (SUD) also meets
criteria for PTSD. Both disorders seem to be highly intertwined. Scientific evidence supports
the assumed functional relationship between PTSD and SUD. Retrospective research has
shown that these patients often started to use substances after the traumatic event, probably to
suppress PTSD symptoms like nightmares and intrusions. In addition, experimental research
indicates that patients experience an increase in (physiological) craving after a confrontation
with personal trauma cues. However, an inverse pattern has also been observed, where PTSD
follows SUD. A possible explanation for this chronology is that substance abuse increases the
risk to encounter dangerous situations that may lead to traumatic experiences and PTSD.
Finally, substance abuse may interfere with the extinction of the traumatic memory,
obstructing trauma reprocessing, and substance abuse may maintain PTSD symptoms of
emotional numbness.
Despite the relatively high prevalence, only 5% of the SUD patients report PTSD
symptoms on their own accord. That means that PTSD is not recognized in the majority of
patients within substance abuse treatment centers. This problem can be solved by active
screening for PTSD. Two chapters of this thesis focus on the development of a screening
questionnaire to detect PTSD within substance abuse treatment centers. For this purpose, a
PTSD screener from the United States army was used, the Primary Care posttraumatic stress
disorder screen (PC-PTSD). In the first study, described in Chapter 2, the PC-PTSD was
translated into the Dutch language. Also, the original screener was extended with a number of
extra items. Firstly, the instruction was extended with a list of traumatic events, so that
patients could mark the events they had experienced. Secondly, 4 extra items were added to
the PC-
these clusters have been associated with substance abuse in former research. Based on the
results of this first study the 4 best items were selected to assemble a new screener: the
Jellinek-PTSD screening questionnaire (J-PTSD). In a next study the J-PTSD was cross-
validated (see Chapter 3). The results of this study indicated a high sensitivity and a high
specificity for the J-PTSD. Both screener studies were carried out within the Jellinek, a large
substance abuse treatment center in Amsterdam, The Netherlands.
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Another subject of this thesis was the treatment of patients with concurrent PTSD and
SUD. Several studies have indicated that SUD treatment may have a positive effect on both
disorders. However, PTSD has shown to be a complicating factor in SUD treatment. PTSD
symptoms have been repeatedly associated with SUD relapse. Consequently, the idea evolved
that these patients could possibly benefit from a combined treatment addressing both
disorders. This has resulted in the development and evaluation of various combined treatment
protocols. Chapter 4 reviews the scientific studies of treatment protocols that were published
in international journals. Until recently most combined treatments were non-trauma-focused.
This means that the aim of treatment was to improve coping skills to manage PTSD
symptoms, and not to reprocess the traumatic experience(s). This approach was in line with
the common concern that trauma-focused PTSD treatment would exacerbate PTSD
symptoms, and would lead to premature treatment dropout. However, no convincing evidence
has been found for the superiority of non-trauma-focused treatment compared to SUD
treatment alone. Interestingly, the few studies evaluating trauma-focused PTSD treatment for
concurrent PTSD and SUD, showed promising, though premature, results. Importantly, no
indications were found for a higher incidence of adverse events or treatment dropout after
trauma-focused PTSD treatment.
Following from the findings described above, two randomized controlled trials (RCTs)
were performed as part of this thesis. Both RCTs examined the effectiveness of trauma-
focused treatment for PTSD combined with SUD treatment (Chapters 5 and 6). The research
was performed within the Jellinek substance abuse treatment center among outpatients and
among inpatients or daycare patients, respectively. The SUD treatment was cognitive
behavioral treatment for SUD. The PTSD intervention was Structured Writing Therapy
(SWT). SWT is a trauma-focused treatment, where structured writing assignments are used to
reprocess the trauma(s) by imaginal exposure, and to reappraise the traumatic event(s) by
cognitive restructuring. It also includes a sharing and farewell ritual to accomplish symbolic
closure of the traumatic event. The writing assignments were discussed with an individual
therapist on a weekly basis. In the outpatient study, the treatment protocols of SUD and PTSD
were integrated. In the inpatient/daycare study, the PTSD treatment protocol was added on to
regular SUD treatment for severe SUD patients. All patients participating in the studies
received psycho-education about the possible functional relationship between PTSD and
SUD. In both studies, the combined treatment for concurrent PTSD and SUD led to
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improvements in PTSD and SUD symptoms. In the inpatient study, the integrated treatment
proved to be more effective than SUD treatment if patients received at least 75% of the
treatment sessions. The trauma-focused intervention was not associated with an increase in
PTSD symptoms or higher dropout rates.
Several recommendations for clinical practice can be derived from the findings in this
thesis. First of all, it is recommended to screen patients systematically for PTSD during the
intake of substance use treatment. In that way, patients can be informed early in treatment
about the functional relationship of PTSD and SUD, and the importance of achieving
abstinence. In addition, it is advised to offer patients the possibility to follow trauma-focused
interventions during SUD treatment. Though, before a patient decides to follow trauma-
focused PTSD treatment, it is crucial to inform him/her about the importance of treatment-
completion. It should be clarified to patients that a regular SUD treatment may also improve
PTSD symptoms, and that a trauma-focused treatment only has added value after treatment-
completion (at least 75% of the sessions).
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SSummary in Dutch
Binnen de verslavingszorg lijdt een relatief grote groep patiënten aan een
posttraumatische stressstoornis (PTSS). Na diagnostisch onderzoek wordt bij ongeveer 1 op
de 4 patiënten PTSS geconstateerd. Problematisch middelengebruik en PTSS lijken sterk met
elkaar verweven te zijn. De vermoede functionele relatie tussen PTSS en problematisch
middelengebruik wordt ondersteund door wetenschappelijke bevindingen. Retrospectief
onderzoek heeft aangetoond dat patiënten met deze comorbiditeit veelal verdovende middelen
zijn gaan gebruiken na een ingrijpende gebeurtenis. Dat is waarschijnlijk om PTSS
symptomen te onderdrukken, zoals nachtmerries en intrusies. Uit experimenteel onderzoek
blijkt bovendien dat deze patiënten meer (fysiologische) trek krijgen in alcohol of drugs na
een confrontatie met herinneringen aan het trauma. Een tegengesteld patroon komt echter ook
uit studies naar voren, waarbij een PTSS volgt op problematisch middelengebruik. Een
mogelijke verklaring voor deze chronologie is dat middelengebruik een verhoogd risico met
zich meebrengt op gevaarlijke situaties die kunnen leiden tot traumatisering en PTSS. Tot slot
is het mogelijk dat middelengebruik interfereert met de verwerking van trauma , doordat het
de extinctie van traumaherinneringen belemmert. Ook zou middelengebruik symptomen van
het PTSS afstomping van de algemene
reactiviteit).
Ondanks dat ongeveer 25% van de patiënten binnen de verslavingszorg een diagnose
heeft voor PTSS, worden de symptomen slechts in 5% van de gevallen spontaan door
patiënten gerapporteerd. Voor een groot aantal patiënten betekent dit dat de klachten
verborgen blijven. Dit kan worden ondervangen door actieve screening op PTSS. Twee
hoofdstukken van dit proefschrift zijn gericht op de ontwikkeling van een korte vragenlijst
(screener) voor het opsporen van PTSS binnen de verslavingszorg. Uitgangspunt voor het
onderzoek was een bestaande screener uit de Verenigde Staten die gebruikt wordt voor het
opsporen van PTSS bij soldaten, de Primary Care posttraumatic stress disorder screen (PC-
PTSD). In de eerste studie, beschreven in hoofdstuk 2, werd deze lijst in het Nederlands
vertaald en met een aantal extra vragen uitgebreid. Allereerst werd er een kader toegevoegd
waarin patiënten konden aangeven welke traumatische gebeurtenissen zij hadden
meegemaakt. Bovendien werden er 4 extra items aan de lijst toegevoegd die betrekking
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reden daarvoor was dat deze clusters in eerdere studies geassocieerd zijn met
middelengebruik. Op basis van de resultaten van deze eerste studie werden de 4 beste items
van de uitgebreide screener geselecteerd en werd op basis daarvan een nieuwe screener
samengesteld: de Jellinek-PTSD screening questionnaire (J-PTSD). De J-PTSD is opnieuw
gevalideerd in een vervolgstudie (zie hoofdstuk 3). De resultaten laten zien dat de J-PTSD
zowel een hoge sensitiviteit als een hoge specificiteit heeft. Beide screeningsonderzoeken
werden uitgevoerd binnen de afdeling curatieve zorg van Jellinek verslavingszorg in
Amsterdam.
Een ander onderwerp van dit proefschrift is de behandeling van patiënten met
comorbide PTSS en problematisch middelengebruik. Uit onderzoek blijkt dat een
verslavingsbehandeling beide stoornissen gunstig kan beïnvloeden. PTSS is echter een
complicerende factor in een behandeling voor middelengebruik. Meerdere onderzoeken
brachten PTSS symptomen in verband met een terugval in gebruik. Hierdoor ontstond het
idee dat deze patiënten mogelijk meer baat hebben bij een gecombineerde behandeling voor
beide stoornissen. Deze visie heeft de laatste jaren aan terrein gewonnen, wat heeft
geresulteerd in de ontwikkeling en bestudering van diverse gecombineerde
behandelprotocollen. Hoofdstuk 4 geeft een overzicht van behandelprotocollen die
wetenschappelijk zijn onderzocht en waarvan de resultaten in internationale tijdschriften zijn
gepubliceerd. Tot voor kort waren dat vooral gecombineerde behandelingen met het doel
patiënten te leren omgaan met PTSS. Hierbij werden geen interventies voor
traumaverwerking aangeboden. Dit had te maken met de heersende bezorgdheid dat
traumagerichte interventies PTSS klachten zouden aanwakkeren en zouden leiden tot het
voortijdig staken van de behandeling. De gecombineerde behandelprotocollen zonder
traumaverwerking hadden echter geen aantoonbare meerwaarde boven een behandeling voor
middelengebruik. Dit in tegenstelling tot de ondervertegenwoordigde studies met
traumagerichte PTSS behandeling die, alhoewel prematuur, hoopvolle resultaten lieten zien
zonder de gevreesde exacerbatie van klachten of uitval.
In het kader van dit proefschrift zijn er, aansluitend op bovengenoemde bevindingen,
twee gerandomiseerde en gecontroleerde studies (RCTs) uitgevoerd naar de effectiviteit van
een traumagerichte behandeling voor PTSS in combinatie met een verslavingsbehandeling
(hoofdstukken 5 en 6). Het onderzoek vond plaats binnen de afdeling curatieve zorg van
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Jellinek verslavingszorg bij respectievelijk ambulante en klinische of dagklinische patiënten.
De behandeling van problematisch middelengebruik bestond uit cognitieve gedragstherapie
(CGT). De interventie voor PTSS was gericht op traumaverwerking met behulp van
gestructureerde schrijfopdrachten (geprotocolliseerde schrijftherapie). Door middel van de
schrijfopdrachten werden imaginaire exposure en cognitieve herstructurering toegepast. Deze
schrijfopdrachten werden wekelijks met een vaste individuele therapeut besproken. Voor de
ambulante groep werden de behandelprotocollen voor problematisch middelengebruik en
PTSS geïntegreerd. Voor de dagklinische groep werd het behandelprotocol voor PTSS
toegevoegd aan de bestaande dagklinische verslavingsbehandeling. Alle participerende
patiënten kregen psycho-educatie over de mogelijke functionele relatie tussen PTSS en
problematisch middelengebruik. In beide studies leidde de gecombineerde behandeling tot een
verbetering van PTSS symptomen en problematisch middelengebruik. Voor de ambulante
groep bleek de gecombineerde behandeling effectiever te zijn dan de reguliere behandeling
voor middelengebruik, mits cliënten minimaal 75% van de behandelsessies hadden gevolgd.
De interventie gericht op traumaverwerking bleek niet tot een toename van PTSS klachten te
leiden en ook niet tot een verhoogde kans op dropout.
Op basis van dit proefschrift kunnen een aantal aanbevelingen worden gedaan voor de
klinische praktijk. Op de eerste plaats is het raadzaam om patiënten systematisch te screenen
op PTSS tijdens de intake van een verslavingsbehandeling. Op die manier kunnen diegenen
met deze comorbiditeit vroegtijdig worden geïnformeerd over de verwevenheid van beide
stoornissen en het daaruitvolgende belang van abstinentie. Daarnaast is het raadzaam om
patiënten tijdens de verslavingsbehandeling de mogelijkheid te bieden een traumagerichte
interventie voor PTSS te volgen. Een goede informatieverstrekking is hierbij van cruciaal
belang. Voordat begonnen wordt met een combinatie behandeling voor PTSS en
problematisch middelengebruik, is het belangrijk om toe te lichten dat een reguliere
verslavingsbehandeling al kan leiden tot een vermindering van PTSS klachten en dat een
combinatie behandeling alleen iets toevoegt als deze (voor minimaal 75% van de sessies)
wordt afgerond.
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DDankwoord [Acknowledgements]
Op de eerste plaats ben ik veel dank verschuldigd aan de proefpersonen die bereid
waren om tijdens, of voorafgaand aan hun behandeling, deel te nemen aan dit onderzoek. De
beschreven inzichten op het gebied van screening en behandeling zijn aan hen te danken.
Deelname aan het onderzoek vergde moed, doorzettingsvermogen en tijd. De grootste
bijdrage aan het proefschrift komt van hen.
onderzoek gefaciliteerd en gesteund, onder wie behandelaren30, intakers31 en
leidinggevenden32. Ook de stagiaires33 en werkstukstudenten34 hebben een grote bijdrage aan
het onderzoek geleverd. Zonder jullie inspanningen, had het onderzoek niet gerealiseerd
kunnen worden.
In het bijzonder wil ik promotor Paul Emmelkamp en co-promotoren Ellen Vedel en
Thomas Ehring bedanken voor hun inspirerende begeleiding. Paul, veel dank voor het
vertrouwen, de scherpzinnige feedback en de gegunde vrijheid bij de uitvoering van de
werkzaamheden. Ellen, jij hebt dit project op ontzagwekkende wijze begeleid en gesteund. Dit
is voor mij van cruciaal belang geweest. Heel veel dank. Thomas, ik kon altijd bij jou terecht
voor doordacht en opbouwend commentaar. Daar heb ik onnoemelijk veel aan gehad. Veel
dank daarvoor.
Verder wil ik Fleur Kraanen bedanken voor de prettige samenwerking bij het
screeningsonderzoek. Ik denk er met plezier aan terug, evenals aan mijn schaarse bezoeken
aan de Roeterstraat. Daarvoor wil ik ook Katherina Meyerbroker en Sandra Raabe bedanken.
Niels Smit wil ik bedanken voor zijn steun bij de data-analyse van de behandelstudies.
30 Syl Oude Egberink, Rens Koetse, Petra Rehwinkel, Dieuwertje Stegeman, Miriam Wilcke, Mirte Heringa, Romy Koch, Evelyn Admiraal, Sandra Mocking, Carlijn de Vries, Sanne Bakker, Kim de Bruijn , Ilja Schurink, Ragna Stam, Geeske Herweijer. 31 Kasper Nikkels, Jacqueline Bouman, Premal Koning, Mariana Poch, Muriel Oude Hengel, Rosa Hulshoff, Mieke Baas, Ellen van Geffen, Nynke Bron. 32 Wencke de Wildt, Matty van der Klooster, Hennie van Hoorn, Miriam Wilcke, Daphne Jongeneel. 33 Annemarijn Poortvliet, Sanne van de Wiel, Jessie de Witt Huberts, Vera van den Brink. 34 Merel Bollen, Jarek van Houten, Janine van Ritbergen, Janske Braun, Lucy Dubelaar, Monique van Rijn, Esra Kayihan,
.
186_Untitled-2.job186_Proefschrift Debora van Dam.job
186
Tot slot wil ik natuurlijk mijn familie en vrienden bedanken, van wie een aantal
mensen in het bijzonder. Op de eerste plaats mijn ouders voor hun betrokkenheid en
praktische steun. Dankzij het vele oppassen op de donderdagen kon ik mij in het laatste jaar
beter op het proefschrift richten. Ook Hans en Mieke wil ik graag bedanken voor alle hulp. Ik
kon altijd op jullie rekenen. Liselotte, Reineke en Inonge dank voor jullie opbeurende
woorden.
Edwin, toegegeven, het schrijven van een proefschrift bleek niet altijd even
romantisch. Dank. Elin, Annelieke en Isa, jullie zijn de allergrootste schatten. Straks heb ik
eindelijk mijn diploma!
PO
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SCREENING AND TREATMENT OF
POSTTRAUMATIC STRESS
DISORDER IN PATIENTS WITH
SUBSTANCE USE DISORDERS
Debora van DamDebora van DamDebora van DamDebora van Dam
Uitnodiging
Voor het bijwonen van deopenbare verdedigingvan mijn proefschrift:
Screening and Treatmentof Posttraumatic Stress
Disorder in Patients with Substance Use Disorders
Op 12 december 2014om 12.00 uur in de
Agnietenkapel van deUniversiteit van Amsterdam,Oudezijds Voorburgwal 231
Amsterdam.
Receptie ter plaatsena afl oop van de promotie.
Debora van [email protected]
Paranimfen:Reineke KunzeLiselotte Boeve