What is Health Psychology?

Health psychology examines how biological, psychological, and social factors interact to influence health, illness, and the way people cope with disease. It emphasises that the mind and body are deeply interconnected and that behaviour and cognition play major roles in overall wellbeing.

Biopsychosocial Model

The biopsychosocial model explains health and illness as products of the interaction between:

• Biological factors – genetics, physiology, immune function
• Psychological factors – thoughts, emotions, beliefs, coping skills
• Social factors – culture, support networks, socioeconomic status

This model contrasts with the biomedical model, which defines health as the absence of disease and focuses exclusively on physical and biological causes.

Focus Areas in Health Psychology

Health psychology research and practice typically centres on:

• How illnesses develop
• Behaviours that maintain or undermine health
• Chronic illness adjustment and management
• Treatment adherence, patient education, and support
• Psychological influences on recovery and resilience

Psychological Influences on Health

Psychological states can either protect or damage physical health:

• Stress, depression, and anxiety can suppress immunity, elevate blood pressure, and increase disease vulnerability.
• Positive emotions, strong coping skills, and social connection can promote healing and resilience.

Common barriers to healthy behaviour include low motivation, low self-efficacy, avoidance, stress, and entrenched habits.

Historical Views of Health

• Hippocrates: believed health reflected balance among the four bodily humours; promoted diet and exercise.
• Plato: proposed mind–body dualism.
• Galen: linked disease to specific organs, dissected animals, but still supported humoral theory.
• Middle Ages: illness interpreted as divine punishment; religious explanations halted medical progress.
• 18th–19th centuries: revival of scientific medicine; breakthroughs in anatomy, the nervous system, and physiology.

Descartes and Pain

Descartes viewed the body as a hydraulic machine. Signals travelled along “nerve threads” to the brain, triggering the release of “animal spirits.”
This early model led to modern understanding of the reflex arc and recognised a link between mind and pain.

Illness–Wellness Continuum

Health exists on a spectrum ranging from severe illness to optimal wellness.
The absence of disease does not guarantee good health — positive wellbeing and functioning also matter.

Stress and Appraisal

Stress is a psychological and physiological response that arises when perceived demands exceed perceived ability to cope.

According to the Yerkes–Dodson Law, moderate stress enhances performance, whereas very low or very high stress causes deterioration.

Cognitive Appraisal

• Primary appraisal: deciding whether an event is irrelevant, benign, or threatening
• Secondary appraisal: evaluating perceived coping resources

A challenge appraisal arises when coping resources seem adequate; a threat appraisal arises when they seem insufficient.

Coping

Coping refers to the cognitive and behavioural efforts used to manage stress or emotional discomfort.

Types of Coping

• Problem-focused coping: tackling the stressor directly
• Emotion-focused coping: managing emotional responses
• Practical vs avoidant coping: moving toward the issue vs avoiding it
• Flexible coping: adapting strategies to the situation

Common Coping Mechanisms

• Reappraisal: shifting interpretation of the situation
• Acceptance: acknowledging what cannot be controlled
• Distraction: redirecting attention
• Rumination: repetitive negative focus (maladaptive)

Effects of Stress

Physiological Effects

• Elevated blood pressure
• Increased cortisol and adrenaline
• Immune suppression
• Fatigue

Behavioural Effects

• Sleep disruption
• Emotional eating or loss of appetite
• Reduced exercise
• Social withdrawal

Religion and Health

Religiosity correlates with improved mental and physical health, potentially due to increased social support, meaning-making, stability, and coping tools.
However, most evidence is correlational, making causation difficult to establish.

Placebo and Nocebo Effects

Placebo effect: Real symptom improvement caused by expectations rather than active treatment ingredients.
Occurs with placebo pills, injections, and even sham surgeries.

Nocebo effect: Negative outcomes arising from negative expectations, even without real harm.

Clinical Trials

Placebos serve as control conditions, allowing researchers to distinguish true treatment effects from expectancy-based improvements.

Explanatory Theories

• Expectancy theory: beliefs shape physiological outcomes
• Conditioning: previous associations with healing trigger bodily responses

Ethical Concerns

Use of placebos can involve deception, compromising informed consent and patient autonomy.

Modern Example: VR for Burn Pain

Snow-themed VR games have been used as a non-pharmacological placebo, redirecting attention and reducing pain perception during burn treatment.