Stress (psychology)

Stress is the physiological and psychological response to perceived challenges or demands (stressors). According to the transactional model of stress and coping developed by Richard Lazarus, stress arises not from the stimulus itself but from a person’s appraisal and interpretation of the situation. Moderate levels of stress can enhance performance by increasing focus, alertness, and motivation, whereas excessive stress can impair psychological functioning and reduce overall performance. Stress elicits physiological, emotional, and behavioral responses. The activation of the sympathetic nervous system triggers the release of catecholamines, whereas the activation of the hypothalamic-pituitary-adrenal axis leads to the release of cortisol. Chronic stress and repeated activation of these hormonal pathways can result in physical harm and diseases. Effective strategies for managing stress include relaxation, exercise, and spirituality.

Definitions

• Eustress: a positive type of stress that results from demands that are perceived as difficult but manageable
• Hormetic stress: an adaptive response to moderate, usually intermittent stress that results in beneficial effects at low doses but is harmful or toxic at high doses
  • Examples: ischemic preconditioning, exercise, dietary energy restriction
• Distress: a negative type of stress that results from demands that are perceived as overwhelming
• Stressor: an internal or external stimulus, event, or condition that triggers a physiological or psychological stress response
  • Significant life changes
  • Cataclysmic events: large-scale, unpredictable events that affect a large number of people
  • Daily hassles
  • Psychological stressors
  • Physiological stressors
• Diathesis: a person's preexisting vulnerability or predisposition to a disease or disorder, which can be due to genetic, psychological, and/or environmental factors
  • Diathesis-stress model: proposes that the combination of a person's predisposition and external stressors leads to the development of mental and physical disorders
• Appraisal: the subjective cognitive process of evaluating a situation to determine its meaning and potential impact on one's well-being

Transactional model of stress and coping

According to the transactional model of stress and coping developed by Richard Lazarus, stress arises not from a stimulus itself, but from a person's appraisal and interpretation of the situation. Stress occurs only when an event is appraised as significantly negative or threatening, and one's coping abilities are perceived as insufficient.

Effect of stress on psychological functions

• Mild levels of stress can enhance performance by increasing focus, alertness, and motivation (see Yerkes-Dodson law).
• Excessive stress can lower performance by impairing psychological functions (e.g., attention, concentration, memory).

Stress elicits physiological, emotional, and behavioral responses.

Physiological response to stress

• Activation of the sympathetic nervous system leads to the release of catecholamines (fight-or-flight or orienting response).
• Activation of the hypothalamic-pituitary-adrenal (HPA) axis leads to the release of cortisol (the primary human stress hormone).
• Homeostasis-allostasis model
  • States that the body is constantly trying to maintain a stable internal state (homeostasis) by actively adjusting physiological systems to accommodate environmental demands (allostasis)
  • While essential for short-term survival, the repeated activation of allostasis due to chronic stress can cause significant, long-term physical harm (allostatic load).

General adaptation syndrome (GAS) by Selye

GAS describes a universal physiological reaction to stressors. This model posits that the response follows a consistent pattern, regardless of the specific stressor.

Emotional response to stress

• Possible responses include:
  • Anger and irritability
  • Anxiety and fear
  • Frustration
  • Feeling of hopelessness and helplessness
  • Sadness
• Chronic stress is a major risk factor for developing mental health disorders such as depression, anxiety disorders, and burnout.
• Psychoendocrine stress model by Henry
  • Describes how an individual's emotional response to a stress stimulus elicits specific endocrine response patterns via activation of two hormonal pathways:
    • Anger, aggression → activation of the sympathetic nervous system → ↑ norepinephrine (fight response)
    • Fear → activation of the sympathetic nervous system → ↑ epinephrine (flight response)
    • Depression, helplessness → activation of HPA axis → ↑ cortisol ("defeat response")
  • States that long-term, repeated activation of each distinct hormonal pathway due to chronic stress leads to different types of physiological damage and diseases:
    • Chronic activation of the sympathetic nervous system → cardiovascular conditions (e.g., hypertension, atherosclerosis)
    • Chronic activation of the HPA axis → metabolic diseases, immune suppression, and depressive disorders

Learned helplessness is a psychological phenomenon in which repeated exposure to uncontrollable events teaches an individual to believe they lack behavioral control over environmental events. As a result, they adopt more passive coping mechanisms and fail to initiate adaptive escape or control behaviors, even when presented with new situations in which control is entirely possible.

Behavioral response to stress

• Possible responses include:
  • Changes in eating behavior
  • Sleep disruption
  • Social withdrawal
  • Aggression
  • Increased substance use

Other concepts

• Concept of response specificity: describes how individuals react to stressors
  • Intraindividual response specificity: A person's response to stressors or stimuli can vary across different situations due to fluctuations in mood, health, or context.
  • Interindividual response specificity: Stress responses can vary significantly between individuals, influenced by differing personalities, coping strategies, and personal experiences.
  • Situational response specificity: Certain stressors can trigger similar reactions in different individuals.
• Concept of critical life events: life changes, whether negative or positive, always require significant adaptation
  • Social Readjustment Rating Scale: provides an objective measurement of the potential stress impact of various life events
  • Psychosocial protective factors help individuals cope with critical life events, whereas psychosocial risk factors make coping more difficult.

Various coping strategies can be employed to manage stress by addressing either the physiological arousal or the cognitive appraisal of stressors.

Physiological management

• Relaxation techniques: Meditation, biofeedback, and yoga actively lower physiological arousal and stress hormone levels.
• Moderate-intensity activities (e.g., jogging or swimming at 60–70% of max heart rate): facilitate the metabolic clearance of circulating catecholamines and cortisol, mitigating the systemic effects of chronic HPA-axis activation
• High-intensity interval training (HIIT): rapid transitions between near-maximal exertion and rest enhance cardiac vagal tone and improve the efficiency of parasympathetic recovery following acute stressors

Cognitive management

• Mindful movement: Low-cognitive-load activities (e.g., yoga, Tai Chi) target secondary appraisal by increasing self-efficacy and grounding the individual in the present moment, which reduces rumination.
• Attentional shifting: High-skill exercises (e.g., rock climbing, tennis) require intense executive function and sensory integration, effectively sequestering cognitive resources away from the appraisal of stressors.
• Cognitive flexibility: helps individuals re-evaluate stressors as manageable challenges rather than overwhelming threats
• Spirituality and faith: can provide a framework for meaning and a source of social support for some individuals