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BRIEF REPORT Brief Report: An Exploratory Study Comparing Diagnostic Outcomes for Autism Spectrum Disorders Under DSM-IV-TR with the Proposed DSM-5 Revision Vicki Gibbs Fiona Aldridge Felicity Chandler Ellen Witzlsperger Karen Smith Published online: 8 June 2012 Ó Springer Science+Business Media, LLC 2012 Abstract The proposed revision for Autism spectrum disorders (ASDs) in the Diagnostic and Statistical Manual of Mental Disorders—Fifth Edition (DSM-5) represents a shift from the Diagnostic and Statistical Manual of Mental Disorders—Fourth Edition, Text Revision (DSM-IV-TR). As the proposed DSM-5 criteria require a higher minimum number of symptoms to be present compared to DSM-IV- TR, there have been some concerns about the impact that this will have on diagnostic outcomes. Therefore, the cur- rent study aimed to compare diagnostic outcomes using both DSM-IV-TR and DSM-5 criteria for 132 children. Of the 111 participants who received an ASD diagnosis under DSM-IV-TR, 26 did not meet DSM-5 criteria. The majority of these had received a DSM-IV-TR PDD-NOS diagnosis. Implications of the results and the proposed DSM-5 changes to the ASD criteria are discussed. Keywords Autism spectrum disorder Á Asperger’s Disorder Á Autistic Disorder Á PDD-NOS Á Assessment Á Diagnosis Á DSM-IV-TR Á DSM-5 Á Social Communication Disorder Introduction The proposed revision for Autism spectrum disorders (ASD) in the Diagnostic and Statistical Manual of Mental Disorders—Fifth Edition (DSM-5, accessible at www.DS M-5.org) has created some controversy in recent times, most notably in relation to the possibility that some indi- viduals who would currently meet criteria under the Diagnostic and Statistical Manual of Mental Disorders— Fourth Edition, Text Revision (DSM-IV-TR; American Psychiatric Association 2000) will no longer meet criteria under the proposed DSM-5. DSM-IV-TR places ASDs under the category of per- vasive developmental disorders (PDDs), which also includes two non-ASD PDDs i.e. Rett’s syndrome and childhood disintegrative disorder. DSM-IV-TR outlines twelve possible ‘‘symptoms’’ of ASD within three areas of impairment, i.e. social interaction, communication and restricted and repetitive interests, activities and behaviors (RRBs). There are three possible ASD diagnoses in DSM- IV-TR i.e. Autistic Disorder, Asperger’s Disorder and Pervasive Developmental Disorder-Not Otherwise Speci- fied (including Atypical Autism; PDD-NOS). These three categories are set out in a hierarchical fashion in DSM-IV- TR whereby Autistic Disorder requires the highest mini- mum symptom set (i.e. at least six characteristics in total across all three areas with at least two from the social interaction area, one from communication area, and one from RRBs and abnormality apparent by age 3 years). A diagnosis of Asperger’s Disorder can be considered once Autistic Disorder is ruled out, requiring at least two social interaction characteristics and at least one characteristic from RRBs. There can be no cognitive or adaptive delay and there must be evidence of functional impairment. If an individual does not meet criteria for Autistic Disorder or V. Gibbs (&) Á F. Aldridge Á F. Chandler Á E. Witzlsperger Á K. Smith Diagnostic Assessment Service, Autism Spectrum Australia (Aspect), PO BOX 361, Forestville, NSW 2087, Australia e-mail: [email protected] F. Aldridge e-mail: [email protected] F. Chandler e-mail: [email protected] E. Witzlsperger e-mail: [email protected] K. Smith e-mail: [email protected] 123 J Autism Dev Disord (2012) 42:1750–1756 DOI 10.1007/s10803-012-1560-6

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Page 1: Brief Report: An Exploratory Study Comparing Diagnostic Outcomes for Autism Spectrum Disorders Under DSM-IV-TR with the Proposed DSM-5 Revision

BRIEF REPORT

Brief Report: An Exploratory Study Comparing DiagnosticOutcomes for Autism Spectrum Disorders Under DSM-IV-TRwith the Proposed DSM-5 Revision

Vicki Gibbs • Fiona Aldridge • Felicity Chandler •

Ellen Witzlsperger • Karen Smith

Published online: 8 June 2012

� Springer Science+Business Media, LLC 2012

Abstract The proposed revision for Autism spectrum

disorders (ASDs) in the Diagnostic and Statistical Manual

of Mental Disorders—Fifth Edition (DSM-5) represents a

shift from the Diagnostic and Statistical Manual of Mental

Disorders—Fourth Edition, Text Revision (DSM-IV-TR).

As the proposed DSM-5 criteria require a higher minimum

number of symptoms to be present compared to DSM-IV-

TR, there have been some concerns about the impact that

this will have on diagnostic outcomes. Therefore, the cur-

rent study aimed to compare diagnostic outcomes using

both DSM-IV-TR and DSM-5 criteria for 132 children. Of

the 111 participants who received an ASD diagnosis under

DSM-IV-TR, 26 did not meet DSM-5 criteria. The majority

of these had received a DSM-IV-TR PDD-NOS diagnosis.

Implications of the results and the proposed DSM-5

changes to the ASD criteria are discussed.

Keywords Autism spectrum disorder � Asperger’s

Disorder � Autistic Disorder � PDD-NOS � Assessment �Diagnosis � DSM-IV-TR � DSM-5 �Social Communication Disorder

Introduction

The proposed revision for Autism spectrum disorders

(ASD) in the Diagnostic and Statistical Manual of Mental

Disorders—Fifth Edition (DSM-5, accessible at www.DS

M-5.org) has created some controversy in recent times,

most notably in relation to the possibility that some indi-

viduals who would currently meet criteria under the

Diagnostic and Statistical Manual of Mental Disorders—

Fourth Edition, Text Revision (DSM-IV-TR; American

Psychiatric Association 2000) will no longer meet criteria

under the proposed DSM-5.

DSM-IV-TR places ASDs under the category of per-

vasive developmental disorders (PDDs), which also

includes two non-ASD PDDs i.e. Rett’s syndrome and

childhood disintegrative disorder. DSM-IV-TR outlines

twelve possible ‘‘symptoms’’ of ASD within three areas of

impairment, i.e. social interaction, communication and

restricted and repetitive interests, activities and behaviors

(RRBs). There are three possible ASD diagnoses in DSM-

IV-TR i.e. Autistic Disorder, Asperger’s Disorder and

Pervasive Developmental Disorder-Not Otherwise Speci-

fied (including Atypical Autism; PDD-NOS). These three

categories are set out in a hierarchical fashion in DSM-IV-

TR whereby Autistic Disorder requires the highest mini-

mum symptom set (i.e. at least six characteristics in total

across all three areas with at least two from the social

interaction area, one from communication area, and one

from RRBs and abnormality apparent by age 3 years). A

diagnosis of Asperger’s Disorder can be considered once

Autistic Disorder is ruled out, requiring at least two social

interaction characteristics and at least one characteristic

from RRBs. There can be no cognitive or adaptive delay

and there must be evidence of functional impairment. If an

individual does not meet criteria for Autistic Disorder or

V. Gibbs (&) � F. Aldridge � F. Chandler � E. Witzlsperger �K. Smith

Diagnostic Assessment Service, Autism Spectrum Australia

(Aspect), PO BOX 361, Forestville, NSW 2087, Australia

e-mail: [email protected]

F. Aldridge

e-mail: [email protected]

F. Chandler

e-mail: [email protected]

E. Witzlsperger

e-mail: [email protected]

K. Smith

e-mail: [email protected]

123

J Autism Dev Disord (2012) 42:1750–1756

DOI 10.1007/s10803-012-1560-6

Page 2: Brief Report: An Exploratory Study Comparing Diagnostic Outcomes for Autism Spectrum Disorders Under DSM-IV-TR with the Proposed DSM-5 Revision

Asperger’s Disorder, then PDD-NOS can be considered.

This is the least stringent of the ASDs outlined in DSM-IV-

TR and requires evidence of severe social impairment

accompanied by either communication impairment or

RRBs. There is no specific minimum number of symptoms

outlined.

The proposed revision for ASDs in DSM-5 consists of a

single category, i.e. Autism spectrum disorder. The ratio-

nale for the removal of the three category system outlined

on the DSM-5 website by the DSM-5 Neurodevelopmental

Work Group is that, although differentiation of ASD from

typical development and other childhood disorders is done

reliably and validly, the distinction between the three cat-

egories has been found to be inconsistent and to vary across

sites (American Psychiatric Association 2011). Certainly,

this is the case in the Australian context. In our clinical

experience some assessment centers have established their

own minimum number of symptoms in order to meet cri-

teria for PDD-NOS; some require at least some sub-

threshold impairment across all three areas while others do

not. Other centers do not necessarily follow the hierarchical

process and diagnose Asperger’s Disorder in any individual

of average cognitive ability who presents with social

impairment and restricted interests. In addition to the var-

iation in application of the current criteria in relation to the

three subtypes, the vast majority of research to date has not

been able to identify meaningful differences between the

subtypes of ASD as outlined in DSM-IV-TR once cogni-

tive ability and language level have been controlled for

(e.g. Allen et al. 2001; First, 2008; Howlin, 2003; Mordre

et al. 2011).

Another proposed change in DSM-5 is reducing the

domains of impairment from three to two by merging the

social interaction and communication domains into a single

domain. This effectively means that the current eight cri-

teria in these areas will be reduced into three criteria. RRBs

will be the second DSM-5 domain and will consist of four

criteria which specifically include unusual sensory behav-

iors. In order to meet criteria for Autism spectrum disorder

under the proposed DSM-5 revision, a child must meet all

three of the social communication impairments and at least

two of the RRBs. According to the DSM-5 Neurodevel-

opmental Workgroup, the rationale for requiring at least

two symptom manifestations from RRBs is to improve

specificity (American Psychiatric Association 2011).

In a recent press release, the American Psychiatric

Association asserted that this improvement in specificity is

not at the expense of sensitivity. Specifically, they stated

that data from DSM-5 field studies do not indicate any

reduction in the number of people ‘‘receiving care for

Autism spectrum disorders in treatment centers’’ (Ameri-

can Psychiatric Association 2012). However, the DSM-5

criteria are more stringent than DSM-IV-TR, requiring a

minimum of five out of seven symptoms to be present. This

is compared to the lowest threshold for a diagnosis of an

ASD under DSM-IV-TR criteria which is currently evi-

dence of social impairment (without any specific symptom

count) and either communication impairment or RRBs or

even sub-threshold presentation across all three areas.

Therefore, there has been some concern about the impact

of the new criteria on diagnostic outcomes.

Several recent studies have indicated that the proposed

DSM-5 criteria will have a significant effect on diagnostic

rates for autism i.e. that individuals who would meet cri-

teria under DSMIV-TR will no longer meet criteria under

proposed DSM-5. McPartland et al. (2012) conducted a

re-analysis of the 933 participants evaluated for possible

pervasive developmental disorder during the DSM-IV field

trials. When they applied the proposed DSM-5 criteria to

this group, they found that 60.6 % of individuals who met

criteria under DSM-IV would meet DSM-5 criteria but

39.4 % of those who met criteria under DSMIV would no

longer meet criteria for a diagnosis of an Autism spectrum

disorder. They found that specificity of the proposed DSM-

5 was very high, with a true negative rate of 94.9 %. When

comparing cases that continued to meet and failed to meet

DSM-5 criteria, there were no differences in gender or age.

However, there was an effect for intellectual ability and

DSMIV subcategory i.e. individuals with an intellectual

disability were more likely than those without an intel-

lectual disability to meet DSM-5 criteria and individuals

with Autistic Disorder were more likely to meet DSM-5

criteria than those with Asperger’s Disorder or PDD-NOS.

The original information for this re-analysis was gath-

ered by clinicians guided by DSM-IV so it is possible that

clinicians did not gather and/or record all information that

would be considered pertinent to DSM-5 criteria. Specifi-

cally, they would not have included questions and/or

investigation of symptoms that will be included in DSM-5

but which are not included under DSM-IV-TR criteria (e.g.

indifference to pain/heat/cold, deficits in understanding

nonverbal communication). Nevertheless, these results

suggest that the proposed DSM-5 criteria may significantly

reduce the numbers of individuals diagnosed with ASD.

Similar findings in terms of reduced sensitivity for DSM-5

compared to DSM-IV criteria were also found in an earlier

epidemiological study in Finland (Mattila et al. 2011). In

this study, only 46 % of cases with an IQ C 50 that had

been identified according to DSM-IV-TR criteria met cri-

teria under the DSM-5 draft criteria. It is important to note,

however, that this study used the DSM-5 criteria posted by

the APA in February 2010, which has since undergone

some refinement.

In another recent study, Worley and Matson (2012) used

checklists to compare ASD symptoms in 121 children

classified according to both DSM-IV-TR and DSM-5

J Autism Dev Disord (2012) 42:1750–1756 1751

123

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diagnostic criteria. They found that there was a subset of

children (59 out of 180 or 32.7 %) who met diagnostic

criteria for an ASD under DSM-IV-TR but no longer met

criteria under DSM-5. Furthermore, they found no signifi-

cant difference in terms of symptom severity between those

who met DSM-5 criteria and those who met DSM-IV-TR

but not DSM-5 i.e. participants who will not meet the pro-

posed future criteria had similar symptom severity to those

who will continue to meet criteria. It is important to note that

this study was based solely on parent-informant checklists

rather than on a comprehensive diagnostic assessment.

Despite this limitation, this study also provides some support

for the prediction that fewer individuals will meet the pro-

posed DSM-5 Autism spectrum disorder criteria.

There is, therefore, some uncertainty around the impact

of the proposed DSM-5 changes to the ASD diagnostic

criteria. While some preliminary research findings suggest

a reduction in the number of individuals who will meet

ASD criteria under DSM-5, the APA have indicated that

the field studies have not found any such reduction

(American Psychiatric Association 2012). Similarly, Fra-

zier et al. (2012) found similar sensitivity and improved

specificity for proposed DSM-5 criteria compared to cur-

rent DSM-IV-TR. Thus, the present study aimed to further

examine the impact of the proposed revision by comparing

diagnostic outcomes for children undergoing comprehen-

sive ASD assessment by trained clinicians cognizant of the

proposed DSM-5 criteria as of January 2011 (American

Psychiatric Association 2011). The primary research

question under consideration was whether the same clini-

cian, faced with the same information about a particular

child, would come to the same diagnostic conclusion under

both DSM-IV-TR and DSM-5 criteria. In addition, the

researchers aimed to explore the reasons for any discrepant

outcomes under the two diagnostic criteria.

Methods

Participants

The sample consisted of 132 children and adolescents referred

to a tertiary-level autism specific assessment service for an

initial diagnostic assessment for autism. Participants ranged in

age from 2 to 16 years (M = 6.06 years, SD = 3.38 years).

Eighty-one percent of participants were male (n = 107) and

19 % were female (n = 25).

Measures

The Autism Diagnostic Observation Schedule (ADOS;

Lord et al. 2002) is a semi-structured assessment tool that

measures communication ability, social interaction, and

play or imaginative skills. The ADOS consists of stan-

dardized activities that allow the clinician to observe

behaviors that have been identified as important in the

diagnosis of Autism spectrum disorders at different

developmental levels and chronological ages. The ADOS

has four modules. The clinician selects the module that is

most appropriate for the particular child or adult based on

their chronological age and expressive language level.

Administration of the ADOS took approximately 45 min.

Notes are taken during the administration of the ADOS and

the clinician assigns ratings at the completion of the

assessment. These ratings assist in the formulation of

diagnosis through the use of the diagnostic algorithm

provided for each module.

The Autism Diagnostic Interview-Revised (ADI-R;

Rutter et al. 2003) is a standardized semi-structured inter-

view that is administered to parents/caregivers regarding

the developmental history and current behavior of the

individual being assessed. The ADI-R consists of 93 items

and focuses on three function domains (language and

communication, reciprocal social interaction, and RRBs).

The administration time for each interview was approxi-

mately 2 h. The ADI–R produces an algorithm which

assists in determining whether or not an individual meets

criteria for a diagnosis of an ASD.

Procedure

The study protocol was approved by Autism Spectrum

Australia’s Ethics Committee. Informed consent was

obtained from parents prior to participation in the study.

The research was conducted during a day-long assessment

for possible Autism spectrum disorder.

The assessment consisted of informal observations, the

ADOS, and the ADI-R. The relevant ADOS module was

administered and, in the case of all children, an ADI-R was

completed with their parents. Assessments were conducted

by Psychologists and Clinical Psychologists of a special-

ized autism assessment service. All clinicians have been

trained in the use of the ADOS and ADI-R for research

purposes and administer them as a routine component of all

assessments.

Firstly, diagnosis was made according to DSM-IV-TR

criteria, with children being classified as having Autistic

Disorder, Asperger’s Disorder, PDD-NOS, or non-ASD.

The diagnostic decision was based on clinical judgment,

which was informed by scores from the ADOS and ADI-R,

along with information gathered from background reports

and teachers or other professionals. This included results of

previous cognitive assessments and/or information

regarding current level of academic functioning, which

were used to infer general cognitive ability for the purposes

of establishing the appropriateness of an Asperger’s

1752 J Autism Dev Disord (2012) 42:1750–1756

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Disorder diagnosis. The individual’s presentation was then

considered, utilizing the same information (i.e. ADOS,

ADI-R, previous assessment reports and teacher back-

ground information) according to the proposed DSM-5

revision for Autism spectrum disorders by the same clini-

cian and a diagnosis of ASD or non-ASD was applied. Age

of onset was determined from ADI-R items pertaining to

first concerns and onset as perceived with hindsight.

Thus for each child, the same clinician using the same

information recorded two diagnostic outcomes i.e. one using

DSM-IV-TR criteria followed by one using proposed DSM-5

criteria. Where clinicians noted discrepancy between DSM-

IV-TR and DSM-5 outcomes, notes were recorded outlining

why the child did not meet criteria under DSM-5.

Data Analysis

The three ASD diagnostic categories under DSM-IV-TR were

collapsed into one group (ASD). Those who did not receive a

diagnosis under DSM-IV-TR were placed into another group

(non-ASD). These DSM-IV-TR diagnostic outcomes were

then compared with DSM-5 diagnoses. Participants were then

divided into two groups—those cases where diagnostic out-

come on DSM-IV-TR was different to outcome on DSM-5

and those cases who had the same outcome on DSM-IV-TR

and DSM-5. An independent samples t test was then utilized to

explore the relationship between the groups and age, and a

Chi-square test was used to explore the relationship between

gender and the two groups. Sensitivity was calculated as the

proportion of children who met criteria under DSM-IV-TR

who also met criteria according to DSM-5. Specificity was

calculated as the proportion of children who did not meet

criteria under DSM-IV-TR and who also did not meet criteria

under DSM-5. Notes by the clinician were also examined to

provide further information regarding the reasons for dis-

crepant outcomes on DSM-IV-TR and DSM-5.

Results

Descriptive Statistics

When considered under current DSM-IV-TR criteria, of the

132 individuals assessed, 59 (44.7 %) met criteria for

Autistic Disorder, 18 (13.7 %) met criteria for Asperger’s

Disorder, and 34 (25.7 %) met criteria for PDD-NOS. In

total, 111 of the 132 (84 %) were diagnosed with an Aut-

ism spectrum disorder under DSM-IV-TR. Twenty-one

(15.9 %) of those assessed did not meet criteria for any

ASD. Outcomes using DSM-5 criteria were then analyzed.

When considered under DSM-5 criteria, 85 (64.4 %) met

criteria for Autism spectrum disorder, while 47 (35.6 %)

did not. Table 1 outlines the diagnostic outcomes accord-

ing to DSM-IV-TR and DSM-5 criteria.

Comparison of Diagnostic Outcomes Under DSM-IV-

TR and DSM-5

Twenty-six of the 111 children (23.4 %) who received a

diagnosis under DSM-IV-TR did not meet criteria when

considered under the proposed DSM-5 criteria. The

remaining 106 children who received a diagnosis under

DSM-IV-TR retained a diagnosis of an Autism spectrum

disorder under proposed DSM-5. When the group that

retained their DSM-IV-TR diagnosis under DSM-5 was

compared to the group who did not retain their DSM-IV-

TR diagnosis under DSM-5, there was no significant dif-

ference in age, t (130) = 1.71, p = 0.09. There was also no

significant difference between the groups in gender, v2 (1,

n = 132) = 0.266, p = 0.606. Of the 26 children who did

not retain their DSM-IV-TR diagnosis under DSM-5, six

had been diagnosed with Autistic Disorder under DSM-IV-

TR, three had been diagnosed with Asperger’s Disorder,

and 17 with PDD-NOS. In order to examine whether there

was a relationship between the original DSM-IV-TR

diagnosis (i.e. Autistic Disorder, Asperger’s Disorder,

PDD-NOS) and meeting or failing to meet criteria under

DSM-5, a t test was conducted. This t test indicated that

DSM-IV-TR diagnostic sub-category was significantly

related to whether or not the child met or failed to meet

DSM-5 criteria, t (109) = -4.61, p \ 0.01. In order to

explore this further, descriptive statistics were examined.

As shown in Table 2, 10.2 % of those diagnosed with

Autistic Disorder, 16.6 % of those diagnosed with Asper-

ger’s Disorder and 50 % of those diagnosed with PDD-

NOS under DSM-IV-TR criteria failed to meet criteria for

any form of ASD under DSM-5. This indicates that,

compared to those diagnosed with Asperger’s Disorder or

Table 1 DSM-IV-TR and DSM-5 diagnostic outcomes

DSM-IV-TR diagnosis n (N = 132) % of those assessed DSM-5 diagnosis N (N = 132) % of those assessed

Autistic disorder 59 44.7 n/a

Asperger’s disorder 18 13.7 n/a

PDD-NOS 34 25.7 n/a

ASD (all above) 111 84 Autism spectrum disorder 85 64.4

Non-ASD 21 15.9 Non-ASD 47 35.6

J Autism Dev Disord (2012) 42:1750–1756 1753

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Autistic Disorder, a higher proportion of children with

PDD-NOS under DSM-IV-TR would fail to meet criteria

under DSM-5.

Sensitivity and specificity for DSM-5 were examined to

compare these properties over the two sets of diagnostic

criteria. As shown in Table 3, when compared to DSM-IV-

TR, DSM-5 criteria had sensitivity of 0.76 and specificity

of 1.0 i.e. DSM-5 correctly identified 76 % of children with

a DSM-IV-TR diagnosis of ASD (true positives) and

100 % of the children who did not have an ASD under

DSM-IV-TR (true negatives).

In an attempt to understand why children who met cri-

teria for an ASD under DSM-IV-TR failed to meet criteria

under DSM-5, the notes of the clinician at the time of the

assessment were examined. The notes indicated that, of the

26 children who did not retain their DSM-IV-TR diagnosis

under DSM-5, 14 failed to meet criteria under DSM-5 due

to insufficient evidence of impairment in RRBs (i.e. only

satisfying 1 of the 4 criteria). The remaining 12 cases were

sub-threshold in terms of the DSM-5 social communication

domain, with the majority of this group (eight children)

displaying largely intact use of nonverbal behaviors, both

currently and according to historical record. The final four

cases did not meet full criteria for either deficits in social

emotional reciprocity or developing and maintaining rela-

tionships as set out in DSM-5.

Discussion

In this sample of 132 children referred for comprehensive

autism assessment, 26 of the 111 (23.4 %) participants who

received a diagnosis under DSM-IV-TR would not meet

criteria as proposed in DSM-5. Similar to the findings of

McPartland et al. (2012) the majority of those who would

miss out under the revised criteria came from the current

PDD-NOS group with 50 % failing to meet new criteria.

The discrepancy rates were lower for Asperger’s Disorder

and Autistic Disorder. For Asperger’s Disorder 16.6 % of

those who received a diagnosis under DSM-IV-TR would

not meet criteria under DSM-5. For Autistic Disorder the

proportion of those with discrepant outcomes was 10.2 %.

There was no relationship between the child’s age or

gender and change in diagnostic status between DSM-IV-

TR and DSM-5. Overall, specificity (or true negatives) for

DSM-5 was very high at 1.0, however this was at some cost

to sensitivity (or true positives) at 0.76.

When examining the reasons for discrepant outcomes

between DSM-IV-TR and DSM-5, 46 % of the children

who received a diagnosis under DSM-IV-TR but not DSM-

5 failed to satisfy all three of the social communication

impairments. These children demonstrated either relatively

intact non-verbal behaviors or were sub-threshold in terms

of meeting the DSM-5 criteria related to their ability to

develop and maintain relationships. The most common

reason for discrepancy in diagnostic outcome was the

failure to meet the set requirement of at least two of the

four RRBs, with 54 % of children who did not retain their

DSM-IV-TR diagnosis only satisfying one of the criteria.

In some cases this was despite presenting with a number of

unusual behaviors such as lining up objects, hand flapping

and stereotyped utterances. Under the proposed criteria all

of the above-mentioned behaviors are included in just one

of the four RRBs criteria, i.e. stereotyped or repetitive

speech, motor movements, or use of objects.

The implication is that children with marked social and

communication difficulties accompanied by several ste-

reotypical behaviors may only meet criteria for one of the

four in the RRBs and therefore not meet full criteria for an

Autism spectrum disorder diagnosis under DSM-5.

Therefore, children with clear support needs that are very

akin to an ASD may have difficulty accessing the necessary

funding, supports, and early intervention programs. This is

consistent with Worley and Matson’s (2012) findings of

similar symptom severity in children who will meet future

criteria compared to those who meet current, but not future,

criteria.

Minor changes to the proposed DSM-5 diagnostic cri-

teria could mean that some of the children whose presen-

tation is similar to that outlined above would be able to

meet all of the proposed criteria and, consequently, access

appropriate supports. For instance, our study suggests that

at least some children who just fail to meet full DSM-5

criteria would meet criteria with a reduction to the

requirement for at least two RRBs down to one RRB.

Alternatively, the creation of one additional RRB criteria

option by separating out some of the multiple behaviors

that are currently grouped together (e.g. separating out

Table 2 Breakdown of discrepant outcomes in DSM-5 by DSM-IV-

TR diagnostic category

DSM-IV-TR category n %

Autistic disorder 6 10.2

Asperger’s disorder 3 16.6

PDD-NOS 17 50

Table 3 Sensitivity and specificity of DSM-5

DSM-IV-TR DSM-5

Non-ASD ASD

Non-ASD n = 21

100 %

n = 0

0 %

ASD n = 26

23.4 %

n = 85

76.6 %

1754 J Autism Dev Disord (2012) 42:1750–1756

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repetitive use of objects from stereotyped language and

motor movements) would allow for additional diagnoses.

These findings would indicate that, without any further

changes, DSM-5 is likely to reduce the number of children

who will be diagnosed with an ASD in the future due to the

more stringent requirements in terms of the number of

criteria that must be met. Results from this study suggest

that the children likely to fall short of meeting full DSM-5

criteria are those who met DSM-IV-TR criteria for PDD-

NOS. The findings highlight the need for comprehensive

assessment, with multiple sources of information including

clinical observation, and information from parents, teach-

ers and other professionals involved with the child. This is

to ensure that adequate information is obtained in order to

satisfy the higher proportion of criteria that will need to be

met under DSM-5.

The rationale behind many of the changes in DSM-5 is

to improve diagnostic consistency and increase the stability

of ASD diagnoses over time. It is possible that many of the

children who would no longer meet ASD criteria under

DSM-5 would instead meet criteria for a diagnosis of the

proposed DSM-5 Social Communication Disorder (SCD).

SCD is conceptualized as a communication disorder and is

characterized by impairments in pragmatics. The propor-

tion of children in this study who may have met criteria for

SCD was not examined as the criteria for SCD have not yet

been clearly operationalized. It could be that this group is,

in fact, quite distinct from those who will meet formal ASD

criteria in DSM-5 with meaningful differences in outcome

and intervention. Alternatively, this group may actually be

more closely aligned to those who meet the full DSM-5

criteria. Future research should aim to examine the simi-

larities and differences between Autism spectrum disorder

as defined in DSM-5 and the proposed Social Communi-

cation Disorder. It is important to examine this, as it would

have implications for the development and implementation

of effective, targeted intervention programs.

There are several limitations to this study that should be

acknowledged. Firstly, there are a number of behaviors that

have long been associated with ASDs that were not for-

mally outlined in DSM-IV-TR and are now included in

DSM-5, e.g. difficulties understanding non-verbal behav-

iors, hypersensitivity to sensory input, indifference to pain/

heat/cold. The assessment tools utilized in this study are

based on DSM-IV-TR criteria. Therefore, information

relating to these newer behaviors may not have been elic-

ited during the assessment process and may have resulted

in an over-estimate of the numbers of children who would

miss out on a DSM-5 diagnosis of ASD. However, clinical

experience is that even without direct questioning, when

these behaviors are evident in a child’s presentation, they

are often volunteered by parents at some point during the

assessment process. Nevertheless, future research into the

effects of the proposed criteria should specifically probe for

new behaviors included in DSM-5. Secondly, the nature of

the sample may limit the generalizability of the results.

That is, as a tertiary referral service many of the cases

represent what may be considered subtler presentations

and/or presentations that may be complicated by the pres-

ence of significant co-morbidities. It could be that the

proportion of those who would not meet criteria for a

DSM-5 diagnosis may be less if cases are taken across the

wider community. Further research utilizing a larger sam-

ple size across a wider community sample would provide

more information. Finally, consideration of a diagnosis

under DSM-5 was always conducted after reaching a

decision according to DSM-IV-TR in this study. Future

studies could evaluate whether arriving at a decision

according to DSM-5 prior to DSM-IV-TR would affect

results.

In conclusion, our findings indicate that there will be

some children who will no longer meet criteria for an ASD

under DSM-5 despite meeting DSM-IV-TR criteria. This

will most likely be those who would currently be diagnosed

with PDD-NOS. As these children do have significant

social communication difficulties, it is possible that they

would meet criteria for SCD. Future research is required to

determine the impact of changes to the diagnostic criteria

on prevalence rates for ASD, funding and treatment

implications, diagnostic practices and comparative out-

comes for children with ASD and SCD.

Acknowledgments This research was presented at the Asia Pacific

Autism Conference (APAC) which was held in Perth, Australia from

8th to 10th of September 2011.

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