Stress and Illness – Comprehensive Study Notes

Health is not merely the absence of disease but a complete state of physical, mental, and social well-being. It sets a holistic benchmark.

Evolved for "fight-or-flight" (rapid energy mobilization). Key structures: Amygdala (threat detection) and Hypothalamus (command center).
Activates SAM axis (adrenaline) and HPA axis (cortisol).
Short-term benefits exist, but chronic psychological stressors lead to persistent activation without physical release.

Stress leads to illness via two pathways:
1. Health-behavior changes: Poor sleep, smoking, alcohol, poor diet, reduced exercise.
2. Physiological activation: SAM + HPA axis activation $\rightarrow$ allostatic load.
These result in health outcomes like cardiovascular disease, infection, and depression.

Acute stress: Short-term, adaptive (e.g., speaking exam).
Chronic stress: Long-term, no clear end (e.g., caregiving); main source of pathology.

Alarm: Initial shock reaction; SAM + HPA activation, adrenaline, cortisol. Adaptive if brief.
Resistance: Body attempts to cope, maintains internal strain with elevated cortisol.
Exhaustion: Energy depleted; leads to immunosuppression, organ damage, and chronic diseases (e.g., hypertension, ulcers).

Kiecolt-Glaser et al. 1996 (Influenza-Vaccine Study): Dementia caregivers had significantly lower influenza vaccine antibody response ( $\approx 35\%$ vs $\approx 60\%$ in controls), showing suppressed efficacy due to chronic stress.
Cohen et al. 1991 (Common Cold): Higher psychological stress correlated linearly with increased infection rates after nasal inoculation; highest-stress group had $\approx 95\%$ infection vs lowest $\approx 74\%$ .
Bereavement & Cardiovascular Events (Carey et al. 2014): Bereaved individuals had double the risk of MI or stroke within months compared to non-bereaved ( $\approx 0.18\%$ vs $\approx 0.09\%$ ).

Events assigned Life Change Units (LCU) (e.g., Death of spouse $100$ ).
Thresholds: $\le 150$ (low risk), $150{-}300$ ( $\sim 50\%$ illness risk), $\ge 300$ ( $\sim 80\%$ illness risk).

Minor, frequent irritations (traffic, queues). Often better predictors of psychological distress than major events.

10 items assessing subjective appraisal of stress (e.g., "How often felt unable to control important things?"). Aligns with Lazarus & Folkman's theory.

Personality influences stress appraisal, then behaviors/physiology, leading to outcomes. Negative affectivity (anger, anxiety) increases perceived stress.

Type A: Competitive, time-urgent, hostile.
Type B: Relaxed, patient.
Rosenman et al. (1976) found Type A individuals had > 2\times higher heart attack incidence (e.g., $\sim11$ vs $\sim5$ events) than Type B, linked to hostility, increased catecholamines, and maladaptive coping.

Stress defined as "demands exceed perceived coping resources." Emphasizes subjective appraisal, suggesting interventions can target demands or resources (e.g., problem-focused vs. emotion-focused coping).

Workplace design: Manage demands and provide recovery.
Healthcare: Prioritize high-risk groups (e.g., caregivers) for preventative interventions.
Public health: Promote stress management as disease prevention.
Equity: Address disproportionate chronic stress in low-SES groups through policy.

Acute stress is adaptive; chronic stress is pathogenic. Stress impacts nearly every body system (immune, cardiovascular) via behavioral and physiological pathways. Measurement is multi-modal (life events, daily hassles