Psychological Stress and Health

Sheldon Cohen

Carnegie Mellon University

WHAT IS STRESS?

Depends who you ask…..

•Biological—SNS Activation (or vagal withdrawal)

or HPA Activation e.g., BP, HR, Skin Conductance, HR variability, Cortisol

•Epidemiological—Objective EventRequires change/adaptationConsensual negative impactDemand/Control

•Psychological—Perceived ThreatDemands exceed ability to copeExperience of stress

HOW DOES STRESS DISEASE?

Environmental Demands(Stressors of Life Events)

Environmental Demands(Stressors of Life Events)

Demands Appraised as Stressful (Perceived Stress)

Environmental Demands(Stressors of Life Events)

Demands Appraised as Stressful (Perceived Stress)

Negative Emotional Response

Environmental Demands(Stressors of Life Events)

Demands Appraised as Stressful (Perceived Stress)

Negative Emotional Response

Activation of SNS &

HPA

Poor Health Practices & Adherence

Environmental Demands(Stressors of Life Events)

Demands Appraised as Stressful (Perceived Stress)

Negative Emotional Response

Activation of SNS &

HPA

Poor Health Practices & Adherence

Dire

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rva

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of C

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Environmental Demands(Stressors of Life Events)

Demands Appraised as Stressful (Perceived Stress)

Negative Emotional Response

Disease RelatedPhysiological Changes

(e.g. immune, cardiovascular)

Activation of SNS &

HPA

Poor Health Practices & Adherence

Dire

ct In

ne

rva

tion

of C

NS

an

d P

hy

sio

log

ica

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Environmental Demands(Stressors of Life Events)

Demands Appraised as Stressful (Perceived Stress)

Increased Risk of Physical and Psychological Disease

Negative Emotional Response

Disease RelatedPhysiological Changes

(e.g. immune, cardiovascular)

Activation of SNS &

HPA

Poor Health Practices & Adherence

Dire

ct In

ne

rva

tion

of C

NS

an

d P

hy

sio

log

ica

l Sy

ste

ms

Environmental Demands(Stressors of Life Events)

Demands Appraised as Stressful (Perceived Stress)

Increased Risk of Physical and Psychological Disease

Negative Emotional Response

Disease RelatedPhysiological Changes

(e.g. immune, inflammatory, cardiovascular)

Activation of SNS &

HPA

Poor Health Practices & Adherence

Dire

ct In

ne

rva

tion

of C

NS

an

d P

hy

sio

log

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Psychological Stress is NOT…

Psychiatric disorders clinical depression, anxiety disorders or PTSD

Personality characteristics hostility, extraversion, neuroticism

Common Measures of Objective Events: Stressful Life Events

Nonspecific Major Stressful Life Events Scales Life Event Interviews (e.g., LEDS, SEPRATE)

Specific Events Bereavement Divorce Natural Disasters Caregiving Job Loss Job Classification (demand/control)

EXAMPLE: Major Stressful Life Events Scales(Item Examples)

Death of a spouse or partnerDeath of a childSeparation or divorceSerious problems at work or schoolArrested or involved in court caseBeing robbedNatural disaster or house fireInvolvement in a serious accidentFired at workBusiness Readjustment

Psychological (appraised) Stress

What is Stress Appraisal?

Primary Appraisal– Is this a threat?Threat (potential for harm)Harm/loss (damage done)Challenge (opportunity for growth, mastery, gain)

Secondary Appraisal-- Can I cope with it?Problem-focused copingEmotional-focused coping

Appraisal depends of stimulus situation & psychological characteristics of individual

Lazarus, R. S., & Folkman, S. (1984) Stress, appraisal & coping.

Common Measures of Perceived Stress

Global Perceived StressDemand/Coping (control)Experiential (negative impact, feel stressed)

Domain SpecificWork Stress

ExperientialDemand/ControlEffort/Reward

Marital or Family Stress

EXAMPLE: Perceived Stress Scale

How often felt nervous and stressedHow often felt on top of thingsHow often felt unable to control thingsHow often felt that your demands exceed

your ability to cope

Cohen, S., Kamarck, T., & Mermelstein, R. (1983). Journal of Health and Social Behavior, 24, 385-396.

EXAMPLE: Job Strain Model(perceptions of demand/decision latitude)

Persons who perceive that they work in environments thatinvolve high demand and allow little latitude or flexibility to meet those demands may develop job strain.

Job DemandsWas your job hectic?Was your job psychologically demanding?

Decision LatitudeCould you make at least one private phone call about 10 minutes or longer during working hours?Could you receive a private visitor for about 10 minutes during working hours?

Do you have control over how to complete your work?When to complete work?

Karasek et al. (1981) Am J Public Health; Landsbergis, et al. (2000). Occupational Medicine: State of the Art Reviews, vol. 15.

Common Measures of Negative Affect

Anxiety, Depression, Anger

Undifferentiated Negative Affect(Suls & Bunde, 2005; Bleil et al, 2008)

Is trait affect chronic stress or dispositional?

EXAMPLE: Negative Affect (POMS)

Sad Depressed Unhappy

On-edgeNervous Tense

HostileResentfulAngry

Maybe undifferentiated affect

Acute versus Chronic Stress

•Hypothesis 2: acute stress can trigger disease events among persons with underlying disease (e.g., asthma, CAD)

•Hypothesis 1: the longer the stressful experience the greater the health risk

•No agreed upon interval at which an acute event becomes chronic

•Hypothesis 3: acute stress is most likely to trigger events in the context of a chronic stressor

Does the durationof the stressor matter?

0

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Rel

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of

a C

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Duration of Life Stressor (in months)

no stressor < 1 > 1, < 6 > 6, < 24 > 24

Cohen et al. (Health Psychology, 1998)

How Many of Us Get Hurt by Stress?

Most people adapt, most of the time

We don't know how much of the slack in prediction is due to:

(a) buffering/modifiers, or

(b) imperfect measurement of initiating circumstances.

What is the evidence (morbidity and mortality studies)?

DepressionCHDHIV/AIDSInfectious Diseases

Wound HealingRheumatoid ArthritisAsthma

Cohen, Janicki-Deverts & Miller, JAMA 2007

Psychological Stress and Depression

Hammen, Annual Review of Clinical Psych, 2005: Mazure, Clinical Psychology, 1998

The association between early onsets and major life stress changes over repeated depressive episodes.

Loss of close others is a particularly potent stressful event in triggering major depression.

Approximately 20-25% of people with major stressful events break down with depression.

Major life events occur 50-80% of the time within 3-6 months of onset (control comparisons are about 20-30%).

Psychological Stress and CHD Risk: Job Stress

(Hemingway & Marmot, BMJ 1999; Kivmaki et al., Scand J Work Enviornment Health 2006; Rozansky et al. Circulation, 1999)

• low control at work, particularly when coupled with high levels of work demand

• The perception of organizational injustice

• An imbalance between the effort people put into work and the rewards they gain

50% increase in CVD risk associated with high levels of work stress

When work stress is defined as:

Psychological Stress and CHD Risk: Acute Stress

Increasing evidence of acute stress triggering clinical events

(MI, Cardiac arythmia, sudden death)For example: 9/11, Northridge earth quake, SCUD Missile attacks, Self-

reported negative emotions (anger) in ambulatory studies

Long-term CVD risk is increased among those experiencing traumatic events (e.g., loss of a child)

and emotional, physical or sexual abuse.

(…Krantz & McCeney, Ann Rev Psychol 2002; Everson-Rose & Lewis. Ann Rev Public Health, 2005)

Psychological Stress and CHD Risk: Depressed & Anxious Affect

Depressive symptoms and future CHD and progression of CHD has been documented in multiple studies

This effect is stronger when CHD is measured as angina, but studies in patients of death and documented MI also are supportive.

Reasonable evidence that anxiety predicts sudden cardiac death in men.

Depression, anxiety and anger may represent a general (nonspecific) disposition that puts persons at risk for heart disease.

Kubzansky & Kawachi in Social Epidemiology, 2000; Suls & Bunde, Psychol Bull. 2005 ; Hemingway & Marmot, BMJ 1999; Rozansky et al. Circulation,1999

Psychological Stress and Infectious Disease: ACUTE URIs

Miller, G. & Cohen, S. (2005). Infectious disease and PNI. In K. Vedhara & M. Irwin (eds.), Human PNI. Oxford Press.

Epidemiology and viral-challenge studies: greater risk for those with major life events or perceived stress.

Some evidence that the longer stressors last the greater the risk.

Social conflicts with friends and family & fellow workers and un- and under-employment are potent stressors

25

30

35

40

45

50

3-4 5-6 7- 8 9-10 11-12

Psychological Stress Index

% w

ith

Co

lds

Cohen, Tyrrell & Smith, New England Journal of Medicine, 1991

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None OtherInterpersonal Work

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Chronic Stressor Domain

Cohen et al. Health Psychology (1998)

Psychological Stress and Infectious Disease: LATENT INFECTIONS

Oral & Genital Herpes

Miller, G. & Cohen, S. (2005). Infectious disease and PNI. In K. Vedhara & M. Irwin (eds.), Human PNI. Oxford Press.

Persistent but not short-term stressors are associated with recurrence.

Effects may be mediated by respiratory infections

Psychological Stress and Infectious Disease: LATENT INFECTIONS

HIV/AIDSAmong HIV positive men, each additional moderately

severe event increases progression to AIDS

Pereira, D. B. & Penedo, F. J. (2005). PNI and chronic viral infection: HIV infection. In K. Vedhara & M. Irwin (eds.), Human PNI. Oxford Press.

Stressful life events have been associated with disease progression and decreased survival in HIV+ individuals

Some evidence for bereavement and depressed affect as risks for disease progression and mortality in HIV+

Who Gets Hurt by Stress?Stress-Buffers or Vulnerability Factors

Demographic Buffers

AgeSocioeconomic StatusRace/Ethnicity

Personality Buffers

Composite indices of Stress-Protective Resources Psychosocial Assets Hardiness (control, commitment & challenge)

Cohen & Edwards, Advances in the Investigation of Psychological Stress, 1989

Interpersonal Factors Social skills Social interests Anomie (alienation)

Personality Buffers

Intrapersonal FactorsGeneralized Expectancies of ControlType A Behavior PatternCoping StylesCoping Flexibility and ComplexityArousal and Sensation SeekingSelf-esteemPrivate Self-ConciousnessStress-Reactivity

Coping Resources as Buffers

Skills and abilities (e.g., analytic, mechanical) Social (people who can provide support) Physical (health & stamina) Tangible Resources (money) Psychological (self-efficacy, perceived control) Institutional, Cultural & Political (agencies, social

groups)

Finding Meaning (finding meaning, Bower… JCCP, 66, 979-986)

S. Folkman et al. (1991) In Eckenrode (ed), The social context of coping.

How do buffers work?

Negative Cognitive and

Emotional Response

Stressful Events

Appraisal of Demands and of Adaptive Capacities

Perceived Stress

Benign Appraisal

Physiological orBehavioral Responses

Physical Disease

PsychiatricDisease

Perceived Availability of Social Resources

Negative Cognitive and

Emotional Response

Stressful Events

Appraisal of Demands and of Adaptive Capacities

Perceived Stress

Benign Appraisal

Physiological orBehavioral Responses

Physical Disease

PsychiatricDisease

Perceived or ReceivedSocial Resources

Negative Cognitive and

Emotional Response

Stressful Events

Appraisal of Demands and of Adaptive Capacities

Perceived Stress

Benign Appraisal

Physiological orBehavioral Responses

Physical Disease

PsychiatricDisease

Perceived or ReceivedSocial Resources

Summary:Buffering/Vulnerability

It is a diverse literature (many possible buffers) and it is not (to my knowledge) currently reviewed.

Most studies of stress and health do not test for buffering or provide appropriate tests

Summary:Buffering/Vulnerability

Because testing for interactions is not standard, negative findings may not be reported.

A large sample is required to test (with sufficient power) the interaction predicted by stress-buffering.

Stress & Health: Some Final Issues

Some impressive demonstrations of associations between stress and disease.

Hint about the role of vulnerability factors/especially social support

Interpretable literatures limited to few major diseases

Some Issues (continued)

A lack of studies addressing behavioral and physiological mediators accounting for links between stress and disease

Limited work defining important parameters of stressful events or perceived stressTypes of StressorsControl and Predictability of StressorsStressor Duration

THE END

“Stressed is just desserts spelled backwards”