Stress and Illness What is the Link?

1. Stress and IllnessWhat is the Link? EPI 6181 February 13, 2008 Roxanne Ward

2. So, what is stress?

3. Definitions • Stress (Hans Selye) • Mechanism – the non-specific response of the body to any demand • Can be good (eustress) or bad (distress) • Stress (Wolf - 1953) • Man’s response to many sorts of noxious agents and threats, including “meaning” for individual • Interaction between organism and environment; dynamic Stress (Taber’s Medical Dictionary) • The result produced when a structure, system is acted upon by a stressor. Generally believed that biological organisms require a certain amount of stress in order to maintain their well-being • Strain (Dictionary) • To injure by making too strong an effort or excessive use

4. Physiology of Stress • Nervous System • Central • Peripheral • Autonomic • Sympathetic • Parasympathetic • Endocrine System • Hypothalamic-pituitary-adrenal (HPA) axis • Sympathetic Adrenal Medulla (SAM) response

5. Autonomic Nervous System

6. Endocrine System • Sympathetic Adrenal Medulla Response Hypothalamus Sympathetic NS Adrenal Medulla Epinephrine & Norepinephrine HR, BP, RR, BS

7. Endocrine System HPA axis Hypothalamus ACTH Adrenal Cortex Glucocorticoids & Mineralcorticoids Protein & Fat Metabolism, BP & Blood volume Inflammatory Response

8. The Pioneers – Their Contributions • Cannon – Physiologist (1920’s) • Homeostasis • A condition which may vary but which is relatively constant • Fight or Flight Response (basic survival instinct) • Fundamental physiologic response to body’s perceived threat to survival

9. The Pioneers – Their Contributions • Hans Selye (1956) • The General Adaptation Syndrome • Different diseases seem to cause similar symptoms = general response • Operates in response to longer term exposure to stress

10. General Adaptation Syndrome SAM activated HPA activated

11. Problems with Response- Based Views • Unable to explain different responses in different individuals • Don’t consider the effect of individual’s perception on the stress response • Circularity of theory

12. Other Important Contributors • Martin Seligman • Learned Helplessness (1967) • Related to lack of control • Richard Lazarus • Cognitive Motivational Relational Theory of Emotion (1986) • Response to stress affected by individual’s thoughts & perceptions – relational phenomenon between individual and environment • Takes into account individual differences in motivational and cognitive variables • Well-known for work on coping

13. Cox (1978) • Stress as a perceptual phenomenon Demand Reappraisal Perception Stress Responses Cognitive/Behavioral Response

14. Problems With Model • How do we account for perceptions of all individuals? • We often respond to stress/demands without conscious evaluation

15. How To Measure Stress? • Three methods to assess role of stress in disease risk: • Environmental – what are the objective conditions that promote stress & lead to disease (stimulus based) • Psychological – based on individual’s interpretation of the meaning of the event and ability to cope Based solely on individual’s perception • Biological – activation of physiologic systems affected by psychological & physically demanding conditions (Stress hormones, cardiovascular response, immune measures)

16. Environmental Perspective • Checklist • Social Readjustment Rating Scale (SRRS) (Holmes & Rahe 1967) • Includes both positive & negative events • Some items could be viewed as symptoms or consequences of illness • Interview Measurement • Allows probing; beneficial when looking at relationship of timing between event and response • Expensive, requires special training

17. Environmental Perspective (2) • Daily & Within Day Event Measures • Assess impact of daily events on physical & mental health • Daily Life Experience (DLE) Checklist • Hassles Scale • Problems with circularity and confounding – some items on scale resemble psychological symptoms • Measurement of Chronic Stressors • Makes sense to link chronic stress to diseases that develop over a period of time • Self Report, Observational, Interviews • Life Events & Difficulty Schedule (LEDS) • Mult-measure may control for measurement error

18. Psychological Perspective • Measurement of stress appraisal • Single-item questions; Self-report scales; Interview-based • How to differentiate appraisal from other psychological processes? • Measurement of affective response • Most common method – Adjective Checklists • Observational methods

19. Biological Perspective • Measurement of Stress Hormones • Epinephrine, norepinephrine; corticosteriods: cortisol, serotonin • Measurement of Cardiovascular Responses • Role in maintaining homeostasis • Blood Pressure, Heart rate, ECG • Measures of Immune Response

20. Stress & Illness Stress linked to: • Cardiovascular Disease • Gastric Ulcers • Hypertension • Viral illness • Cancer? • Anxiety • Depression

21. Stress: The Illness Connection • Link between breast cancer & stress? • Potential relation between stress and risk of breast cancer – different study designs, conflicting results • Risk of breast cancer and acute stress of major life events, but less attention to effect of perceived “daily stress” • 2005 – Self Reported stress & risk of breast cancer: prospective cohort study • Reduced risk of breast cancer • 2004 – Job stress & breast cancer risk • Job stress not related to increase in breast cancer risk

22. Social Stress • Origins • Individual experiences of ongoing strains & negative events within social roles are products of social stratification by gender, race, social class • Outcome of social organization – systematic discrimination & inequity • Are members of lower class groups physically more vulnerable to effects of stressors?

23. Social Status & Illness: Is Stress the Path Between? • Summary of literature (Thoits) • Experience of negative major life events & chronic difficulties risk of psych problems & physical illness • Sense of personal control over life circumstances psych symptoms & acts as buffer • Social integration probability of morbidity & mortality • Perceived emotional support psych symptoms & acts as buffer to neg. events & chronic strains

24. Research • 2008 – The influence of active coping & perceived stress on health disparities in a multi-ethnic low income sample • Higher perceived stress related to poorer general health for all ethno-racial groups • Perceived stress critical component in understanding health outcomes

25. Research • 2007 – Subjective social status (SSS), objective SES & cardiovascular risk in women • Women with SSS had more cardiovascular risk behaviors • Evidence that perception of one’s social status could have important health implications beyond objective SES

26. References • Cohen S, Kessler RC, Gordon LU. Measuring stress. New York: Oxford University Press, 1995. • Thoits PA. Stress, coping, and social support processes: where are we? What next? J Health Soc Behav 1995;36(Suppl):53. • Lazarus RS, From psychological stress to the emotions: A history of changing outlooks. Annu Rev Psychol 1993;44:1-21. • Cassel J. Psychosocial processes and “stress”: theoretical formulation. Int J Health Serv 1974;4:471:82 • Dohrenwend BP, Shrout P. “Hassles” in the conceptualization and measurement of life stress variables. Am Psychol 1985;40:780-785. • Theorell T, Karasek RA. Current issues relation to psychosocial job strain and cardiovascular disease research. J Occup Health Psychol 1996;1:9-26. • Cooper CL, Faragher EB. Psychosocial stress and breast cancer. In: Plotnikoff N, ed. Stress and immunity. Boca Raton: CRC Press Inc, 1991:259-282. • Watson J, Logan H, Tomar SL. The influence of active coping and perceived stress on health disparities in a multi-ethnic low income sample. BMC Public Health 2008; 8: 41. • Schernhammer E, Hankinson S. Job stress and breast cancer risk; The nurses’ health study. Am J Epi 2004;160:1079-1086. • Ghaed SG, Gallo LC. Subjective social status, objective socioeconomic status and cardiovascular risk in women. Health Psychol 2007;26(6):668-674.