Premed · Premed · Introductory Psychology
Lecture 16: Stress and Health Psychology
Introductory Psychology
Learning Objectives
By the end of this lecture, students will be able to:
- Define stress and identify the major types of stressors
- Describe the body's physiological stress response including the general adaptation syndrome
- Explain how stress affects the immune system and physical health
- Identify personality and psychological factors that moderate the stress-health relationship
- Describe effective coping strategies and health-promoting behaviors
Lecture Content
I. What Is Stress?
Stress is the process by which we perceive and respond to events — called stressors — that we appraise as threatening or challenging. Stressors come in several forms. Catastrophic events include large-scale disasters such as earthquakes, wars, and pandemics. Significant life changes encompass events like the death of a loved one, divorce, job loss, or moving; the Holmes and Rahe Social Readjustment Rating Scale (SRRS) quantifies these changes in life change units, which correlate with subsequent illness. Daily hassles are the minor irritations of everyday life — traffic, deadlines, arguments — and Lazarus's research suggests that these may actually be better predictors of health than major life events. Chronic stressors are ongoing conditions such as poverty, discrimination, caregiving responsibilities, or chronic illness.
Whether an event is experienced as stressful depends critically on appraisal, as described by Lazarus and Folkman. Primary appraisal asks, "Is this event a threat, a challenge, or irrelevant?" Secondary appraisal asks, "Do I have the resources to cope?" The same event can be highly stressful for one person and entirely manageable for another, depending on how they appraise it. A sense of perceived control over stressors reduces the stress response, and its absence is associated with learned helplessness, depression, and poorer health outcomes. Even an illusion of control can buffer against the harmful effects of stress.
II. The Physiology of Stress
Walter Cannon described the fight-or-flight response, the body's rapid mobilization in the face of perceived threat. The sympathetic nervous system activates, and the adrenal medulla releases epinephrine and norepinephrine, producing increased heart rate, blood pressure, respiration, blood glucose, and muscle tension, while suppressing digestion and immune activity. Shelley Taylor proposed an alternative stress response, the tend-and-befriend response, which is particularly prominent in females and involves nurturing offspring and forming social alliances. This response is mediated by oxytocin.
The HPA axis (hypothalamic-pituitary-adrenal axis) provides a slower but more sustained stress response. The hypothalamus releases CRH, which stimulates the pituitary to release ACTH, which in turn triggers the adrenal cortex to release cortisol. Cortisol mobilizes energy and suppresses immune function, but prolonged elevation is harmful, damaging the hippocampus and contributing to numerous health problems.
Hans Selye's General Adaptation Syndrome (1936) describes the body's response to prolonged stress in three stages. The alarm reaction involves initial shock followed by rapid mobilization of the fight-or-flight response. During the resistance stage, the body adapts and appears to cope, but resources are being progressively depleted. In the exhaustion stage, prolonged stress has depleted the body's resources, leaving it vulnerable to illness, organ damage, and collapse. Selye emphasized that the stress response is nonspecific — different stressors produce the same general physiological pattern — though his model has been criticized for not accounting for psychological appraisal or individual differences.
<image>A diagram of the General Adaptation Syndrome (GAS) showing the three stages. The x-axis represents time and the y-axis represents resistance to stress. Panel A: Alarm phase — resistance drops below normal (initial shock) then rapidly rises as the body mobilizes. Panel B: Resistance phase — resistance is elevated above normal as the body copes with the stressor; a plateau is shown. Panel C: Exhaustion phase — resistance declines sharply below normal as resources are depleted; icons of illness, organ damage, and vulnerability appear. Below the graph, a separate diagram shows the HPA axis: hypothalamus → CRH → pituitary → ACTH → adrenal cortex → cortisol, with a negative feedback loop from cortisol back to the hypothalamus and pituitary.</image>
III. Stress and Health
Psychoneuroimmunology (PNI) is the field that studies how psychological factors, the nervous system, and the immune system interact. Short-term stress can temporarily boost immune function, but chronic stress suppresses it through sustained cortisol release, reducing lymphocyte activity (B cells, T cells, and natural killer cells), slowing wound healing, and increasing susceptibility to illness. Cohen and colleagues (1991) demonstrated that participants under high stress were significantly more likely to develop colds after exposure to a virus. Chronic stress also promotes inflammatory processes that are linked to cardiovascular disease, diabetes, and cancer.
Chronic stress contributes to cardiovascular disease through a pathway of elevated blood pressure, atherosclerosis, and ultimately heart attack or stroke. Friedman and Rosenman identified the Type A personality pattern — characterized by competitiveness, time urgency, hostility, and impatience — as a risk factor for heart disease, with the hostility component being the strongest predictor. Type B individuals are more relaxed and easygoing. Type D (distressed) personality, characterized by negative emotions combined with social inhibition, has also been linked to poor cardiac outcomes.
On the mental health front, chronic stress is a major risk factor for depression, anxiety disorders, and PTSD. The diathesis-stress model explains how stress can trigger the onset of disorders in genetically predisposed individuals.
IV. Psychosocial Factors Moderating Stress
Several psychological and social factors moderate the relationship between stress and health. Optimists tend to have better health outcomes, faster recovery from illness, and stronger immune function, partly because they attribute setbacks to external, unstable, and specific causes. Hardiness, a concept developed by Kobasa, comprises three components — commitment (active engagement with life), control (belief in one's ability to influence events), and challenge (viewing change as an opportunity rather than a threat) — and is associated with greater resistance to stress-related illness.
Social support is one of the strongest buffers against stress. It comes in several forms: emotional support (empathy and caring), instrumental support (tangible aid), and informational support (advice and guidance). Social support reduces cortisol, blood pressure, and inflammatory markers. Conversely, loneliness and social isolation are significant risk factors for mortality, comparable in magnitude to smoking. Religiosity and spirituality are associated with greater social support, a sense of meaning, and healthier behaviors, though these correlations may partly reflect third variables such as community involvement. Antonovsky's concept of sense of coherence — the belief that life is comprehensible, manageable, and meaningful — also predicts resilience.
V. Coping Strategies
Problem-focused coping involves taking direct action to address the stressor — planning, seeking information, and confronting the problem. It is most effective when the situation is controllable. Emotion-focused coping involves managing the emotional response through strategies such as reappraisal, seeking social support, relaxation, acceptance, and humor, and is more appropriate when the situation is uncontrollable. Maladaptive coping strategies — avoidance, denial, substance use, and aggression — may provide temporary relief but typically worsen long-term outcomes.
Evidence-based stress management techniques include exercise (which reduces cortisol and releases endorphins), relaxation techniques (progressive muscle relaxation, deep breathing, meditation), biofeedback (learning to control physiological processes through electronic monitoring), cognitive restructuring (identifying and challenging irrational or catastrophic thoughts), and effective time management.
VI. Health-Promoting Behaviors
Regular physical exercise — with 150 minutes per week of moderate activity recommended — reduces the risk of cardiovascular disease, diabetes, depression, and cognitive decline. A balanced diet supports immune function, brain health, and disease prevention. Adequate sleep (7-9 hours for adults) is essential for immune function, memory consolidation, and emotional regulation. Avoiding substance misuse, including tobacco, excessive alcohol, and drug use, significantly reduces disease risk.
Behavioral medicine is the interdisciplinary field that integrates behavioral and biomedical knowledge to promote health. Health psychology focuses specifically on how psychological factors influence health, illness, and health-related behaviors. The stages of change model, developed by Prochaska and DiClemente, describes behavior change as progressing through five stages: precontemplation, contemplation, preparation, action, and maintenance. Relapse is considered a normal part of the change process, not a failure.
<image>An infographic on stress, coping, and health. Panel A: Two pathways from a stressor — one through problem-focused coping (controllable situation) showing direct action steps, and one through emotion-focused coping (uncontrollable situation) showing reappraisal, social support, and relaxation. Panel B: A balance scale with stress factors on one side (chronic stressors, lack of control, social isolation, pessimism) and protective factors on the other side (social support, optimism, exercise, perceived control, hardiness), with health outcomes tipping toward whichever side is heavier. Panel C: The stages of change model shown as a circular diagram with the five stages (precontemplation, contemplation, preparation, action, maintenance) arranged around the circle with arrows showing progression and a relapse arrow cutting back to earlier stages.</image>
