Stress as a Psychobiological Process

Understanding Stress

• Definition: Stress is a state of physiological and psychological arousal produced by internal or external stressors that are perceived by the individual as challenging or exceeding their ability to cope.

• Psychobiological Process: Stress is considered a psychobiological process because it involves both psychological (mental) and biological (physiological) components.

  • Psychological Components: Cognitive appraisal, perception of threat, emotional responses (e.g., fear, anxiety).
  • Biological Components: Activation of the nervous system (e.g., sympathetic nervous system) and endocrine system (e.g., release of cortisol).

KEY TAKEAWAY: Stress is a complex interaction between our minds and bodies, not just one or the other.

Stressors

• Definition: Stressors are any event, situation, or stimulus that causes stress. They can be internal or external.

• Internal Stressors: Originate within the individual.

  • Examples: Personal beliefs, thoughts, feelings, physical illness.

  • External Stressors: Originate outside the individual.

  • Examples: School, work, relationships, environment.

Types of Stressors

• Eustress: A positive psychological response to a stressor, as indicated by the presence of positive psychological states (e.g., feeling enthusiastic, motivated, excited, active and alert).

  • Motivates, focuses energy.
  • Short-term.
  • Perceived as within coping abilities.
  • Examples: Taking on a challenging project, preparing for a performance.

  • Distress: A negative psychological response to a stressor, as indicated by the presence of negative psychological states (e.g., anger, anxiety, irritability, tension, distress).

  • Causes anxiety or concern.

  • Can be short- or long-term.
  • Perceived as exceeding coping abilities.
  • Examples: Dealing with a relationship breakdown, managing financial problems.

EXAM TIP: Understand the difference between eustress and distress and be able to provide examples of each.

The Stress Response

• Definition: The physiological and psychological reactions that occur when an individual perceives a stressor.
• Involves two major systems:
  • Nervous System: Particularly the autonomic nervous system (ANS) and its sympathetic branch.
  • Endocrine System: Particularly the hypothalamic-pituitary-adrenal (HPA) axis.

Physiological Responses

• Autonomic Nervous System (ANS):

  • Controls involuntary bodily functions.
  • Sympathetic Nervous System (SNS): Activated during stress.
    • Releases adrenaline and noradrenaline.
    • Increases heart rate, blood pressure, respiration rate.
    • Dilates pupils.
    • Slows digestion.
  • Parasympathetic Nervous System (PNS): Returns the body to a state of calm after the stressor is removed.

• Endocrine System:

  • HPA Axis:
    • Hypothalamus activates the pituitary gland.
    • Pituitary gland releases ACTH (adrenocorticotropic hormone).
    • ACTH stimulates the adrenal glands.
    • Adrenal glands release cortisol.
  • Cortisol:
    • Increases energy supplies (e.g., by releasing glucose).
    • Suppresses the immune system.
    • Prolonged release can have negative effects on physical and mental health.

COMMON MISTAKE: Confusing the roles of the sympathetic and parasympathetic nervous systems. The sympathetic system prepares the body for “fight or flight,” while the parasympathetic system returns it to a state of calm.

Psychological Responses

• Emotional: Feelings such as fear, anxiety, frustration, or anger.
• Cognitive: Changes in attention, concentration, and memory.
• Behavioral: Actions such as avoiding situations, seeking support, or engaging in coping strategies.

General Adaptation Syndrome (GAS) - Hans Selye

• A model describing the physiological response to chronic stress.
• Three stages:
  1. Alarm Reaction:
     • Initial response to the stressor.
     • Shock: Body temperature and blood pressure drop; ability to cope is reduced.
     • Countershock: SNS activated; fight-flight-freeze response.
     • Adrenaline released, increased heart rate, etc.
  2. Resistance:
     • Body attempts to adapt to the stressor.
     • Cortisol released to energize the body and repair damage.
     • SNS activity decreases, but body remains on high alert.
     • Immune system is suppressed.
  3. Exhaustion:
     • Prolonged stress depletes resources.
     • Resistance to stress declines.
     • Increased vulnerability to illness, fatigue, and mental disorders.
     • Body can no longer sustain the elevated level of arousal.

STUDY HINT: Create a table or diagram to visually represent the stages of GAS and their associated physiological responses.

Limitations of GAS

• Assumes all individuals have the same general adaptation responses to stress.
• Does not account for individual psychological factors (e.g., cognitive appraisal).
• Primarily based on research with animals, which may not fully generalize to humans.

Lazarus and Folkman’s Transactional Model of Stress and Coping

• Emphasizes the importance of cognitive appraisal in determining the stress response.
• Stress is viewed as a transaction between the individual and the environment.
• Two types of appraisal:
  1. Primary Appraisal: Evaluating the significance of the stressor.
     • Is it irrelevant, benign-positive, or stressful?
     • If stressful, is it a harm/loss, threat, or challenge?
       • Harm/Loss: Damage that has already occurred.
       • Threat: Potential for future harm/loss.
       • Challenge: Opportunity for growth or gain.
  2. Secondary Appraisal: Evaluating coping resources and options.
     • Can I cope with this stressor?
     • What resources are available to me?
     • What coping strategies can I use?

Coping Strategies

• Problem-Focused Coping: Managing or altering the source of the stress.

  • Examples: Taking direct action, planning, seeking information.

  • Emotion-Focused Coping: Managing the emotional response to the stressor.

  • Examples: Denial, distancing, venting emotions, seeking emotional support.

REMEMBER: The Transactional Model highlights that stress is subjective and depends on how we interpret and cope with stressors.

Strengths of the Transactional Model

• Acknowledges the subjective nature of stress.
• Explains why different people respond differently to the same stressor.
• Emphasizes the role of cognitive appraisal and coping strategies.

Limitations of the Transactional Model

• Difficult to test empirically due to the subjective nature of appraisal.
• Overlooks the physiological components of the stress response.
• Does not fully explain how coping strategies influence the stress response.

APPLICATION: The Transactional Model can be used to understand how individuals perceive and cope with stress in various situations, such as academic pressure, relationship problems, or workplace challenges.

Factors Influencing the Stress Response

• Prior Experience: Previous exposure to stressors can influence how individuals respond in the future.
• Personality: Certain personality traits (e.g., optimism, resilience) are associated with better coping.
• Coping Strategies: The effectiveness of coping strategies can influence the intensity and duration of the stress response.
• Social Support: Having strong social connections can buffer the effects of stress.

VCAA FOCUS: VCAA exams often include scenarios where students must apply their understanding of stress models (GAS and Transactional) to explain individuals’ responses to specific stressors.