Stress

Definition of Stress

  • Selye (1976) defined stress as "the nonspecific response of the body to any demand."

  • Stress can vary among individuals and is influenced by factors such as environmental threats, workplace challenges, life events, or personality traits.

Why Do We Experience Stress?

  • Some stress is necessary to keep us alert and occupied.

  • Intense or prolonged stress can lead to harmful psychological and physical effects.

How Stress Affects the Body

The Nervous System

  • Central Nervous System: Comprises the brain and spinal cord.

  • Peripheral Nervous System: Comprises the somatic and autonomic systems.

  • Autonomic Nervous System (ANS): Regulates involuntary functions like heart rate, digestion, and blood pressure.

    • Sympathetic Branch: Activates the "fight-or-flight" response during stress.

    • Parasympathetic Branch: Promotes "rest-and-digest" activities, aiding in recovery.

Effects of the Sympathetic and Parasympathetic Systems

  • Sympathetic Activation:

    • Heart rate increases, breathing becomes fast and shallow, pupils dilate, and blood is redirected from the skin to muscles.

  • Parasympathetic Activation:

    • Heart rate slows, breathing is full and slow, digestion is active, and energy is conserved.

Stress Response Mechanism

  • The Hypothalamus releases noradrenalin, activating the sympathetic branch of the ANS.

  • The adrenal medulla releases adrenaline and noradrenaline into the bloodstream, preparing the body for action.

  • Pituitary-Adrenal System: If stress becomes chronic, the hypothalamus stimulates the pituitary gland to release ACTH, leading to cortisol production from the adrenal cortex.

General Adaptation Syndrome (GAS)

  • Proposed by Selye (1936) after studies on lab rats, highlights the body's response to stress in three stages:

    1. Alarm Stage: Immediate reaction to stress where the body prepares 'fight or flight.'

    2. Resistance Stage: Body attempts to adapt to stress; symptoms may diminish, but health risks increase.

    3. Exhaustion Stage: Prolonged stress leads to breakdown; risk of stress-related illnesses increases.

Sources of Stress

Life Events

  • Holmes and Rahe (1970) noted that significant life events (both positive and negative) can cause stress due to the required transitions.

    • Their study found a correlation between stressful life events and illness incidence.

Workplace Stress

  • Causes include long hours, job security issues, work relationships, and lack of access to resources.

    • Study by Chandola et al. (2008) showed a significant link between work stress and coronary heart disease (CHD) in those aged 37–49.

Personality Types

  • Friedman and Rosenman (1978) identified:

    • Type A: Competitiveness, time urgency, and higher hostility.

    • Type B: Relaxed, less driven, and more tolerant. Personality influences stress reactivity.

Issues & Debates

Free Will vs. Determinism

  • Examines whether behavior is shaped by choices (free will) or influenced by external/internal factors (determinism).

  • The concept of stress incorporates both viewpoints—while stressors can be external, individuals can make healthier choices.

Example Studies

Johanssen et al. (Swedish Mill Workers Study)

  • Investigated stress levels and productivity among sawmill workers, finding higher stress levels in skilled workers leading to physiological and psychological impacts.

Burnout

  • Defined as emotional, physical, and mental exhaustion, often seen in professions dealing with high-stress situations (e.g., healthcare).

  • It results from excessive and prolonged stress, leading to feelings of being overwhelmed and drained.