Stress and Illness

January 23, 2018 | Author: Anonymous | Category: Science, Health Science, Immunology
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Stress and Illness – Overview • What is the relationship between stress and illness? – Stress and changes in physiology – Stress and changes in behaviour

• Moderating factors: e.g., coping, social support, personality and control • Stress: Portrait of a Killer, National Geo DVD

Stress and Illness – Key point If you repeatedly turn on the stress-response, or if you cannot appropriately turn off the stress-response at the end of a stressful event, the stress-response can eventually become as damaging as some stressors themselves. A large percentage of stress-related diseases are disorders of excessive stress-response. Robert Sapolsky – Why Zebras Don’t Get Ulcers

Psychophysiological model of the stress response

Fig. 1. Negative emotionality in children with one of two brain-derived neurotrophic factor (BDNF) genotypes—valine (val) homozygous or at least one methionine (met) allele—as a function of the presence or absence of parental depression (n = 400).

Hayden E P et al. Psychological Science 2010;0956797610385357 Copyright © by Association for Psychological Science

Fig. 2. Negative emotionality in children with one of two brain-derived neurotrophic factor (BDNF) genotypes—valine (val) homozygous or at least one methionine (met) allele—as a function of the presence or absence of parental discord (n = 332).

Hayden E P et al. Psychological Science 2010;0956797610385357 Copyright © by Association for Psychological Science

Psychophysiological model of the stress response

Psychophysiological model of the stress response

This acute response is not typically problematic. Chronically, however, it’s a different story…

Health Consequences of Chronic Stress SAM   BP, HR, epi) HPA  immunosuppression

Coronary Heart Disease and Stress • Rates of CHD is higher in those with high stress jobs. Why? – BP chronically elevated (wear and tear!) – Epi  circulating platelets clump together – Atherosclerosis (plaques)

• Kaplan’s research with monkeys (re: social stress & unstable hierarchy -- low control)

Research study: “Overload in Working Mothers” • BCBS workers • Measures: – Urine samples (to look for metabolites of stress hormones) – Daily mood scale • Results: feel stressed (esp w/ children at home) – High stress (low perceived control + high demand) – increased urinary neurohormones

Immunity and Stress

T cell

Immune System Overview

Psychoneuroimmunology (PNI) • Subfield of health psychology that emphasizes the interaction of psychological, neuroendocrine, and immunological processes in stress and illness

PNI: From stressor to illness • We differ as to the pattern and frequency of stressors to which we are exposed • These variations determine the magnitude and frequency with which we turn on the stressresponse • The magnitude and frequency of the stress response regulate immune competence (e.g., via glucocorticoids) • Level of immune competence determines susceptibility to disease

PNI Studies • Immunosuppression has been linked to divorce, bereavement, unemployment, exam periods, occupational stress, and stressful bouts of exercise – e.g., Life stress and exposure to cold viruses • Wound studies (Kiecolt-Glaser)

• Animal studies show that tumor cells grow more rapidly in animals exposed to electric shock, loud noise, or other stressors

Sapolsky’s baboons • High and Low Social Status – High cortisol is associated with low social status (instability and less controllability) – Low status – Fewer lymphocytes and weak immune system

Sapolsky’s baboons Studies with dominant male baboons suggest that attitude (“personality”) is a more important mediator of physiology than rank alone (i.e., just being alpha male isn’t necessarily good, if one is high-strung about it…)

Moderators of the stress-illness relationship Perception / Appraisal Personality Social Support Control Coping skills

How do these relate to you? What gets you “stressed” and why?

Moderators of the stress-illness relationship: Perception Many situations are not inherently stressful… depends on appraisal: Primary appraisal — determination of an event’s meaning Secondary appraisal — evaluation of one’s ability to meet the demands of a challenging event Cognitive appraisals are extremely susceptible to one’s current state of mood, health, motivation

Perception and stress “I have had a great many troubles in my life…

And most never happened…” Mark Twain

Developing Coping Skills Increasing social support Time management Emotion-focused coping or problem-focused coping

Reducing the impact of the stress reaction Etc…

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