Pain Psychology and Health Behaviour Change

Welcome to Psychological Medicine, Module 8 of ELM2. This first lecture covers the psychology of pain and the theory behind changing health behaviour — two areas that fundamentally shape how patients experience illness and how clinicians can help.

PAIN PSYCHOLOGY

Pain is one of the most common reasons patients present to doctors, yet it is frequently misunderstood. We distinguish between acute pain and chronic pain not merely by duration but by underlying mechanism and psychological context.

Acute pain is predominantly nociceptive — a protective signal arising from tissue damage or threatened damage. It is time-limited, correlates reasonably well with tissue pathology, and responds to analgesia and treatment of the underlying cause. In contrast, chronic pain (conventionally lasting more than three months) frequently becomes decoupled from tissue pathology. The nervous system undergoes central sensitisation: spinal cord neurons become hyperexcitable, pain thresholds fall, and stimuli that were previously innocuous become painful (allodynia).

The biopsychosocial model of pain, developed by Engel and extended by Waddell for back pain, holds that the pain experience is shaped by three interacting domains. Biological factors include nociception, inflammation, and neural sensitisation. Psychological factors include catastrophising (a tendency to ruminate on pain and view it as overwhelming), fear-avoidance beliefs (avoiding movement because of fear of re-injury), depression, and anxiety. Social factors include work demands, litigation, social isolation, and cultural attitudes to pain expression. A striking demonstration of these interactions is the fact that psychological distress predicts the transition from acute to chronic low back pain more strongly than MRI findings do.

Pain catastrophising — measured by the Pain Catastrophising Scale — comprises three components: rumination ("I cannot stop thinking about the pain"), magnification ("The pain is terrible and I feel it will never get better"), and helplessness ("There is nothing I can do to reduce my pain"). Catastrophising is an independent predictor of disability, analgesic consumption, and poor surgical outcomes.

Fear-avoidance is a cognitive-behavioural cycle. The patient experiences pain, interprets it as signalling harm (catastrophic misinterpretation), fears movement, avoids activity, becomes deconditioned, and experiences more pain — completing a vicious cycle. Graded exposure and physiotherapy aim to break this cycle.

HEALTH BEHAVIOUR CHANGE

Health behaviour change theory explains why patients do or do not adopt healthy behaviours — taking medications, exercising, stopping smoking — and guides clinicians toward effective interventions.

The Transtheoretical Model (Stages of Change, Prochaska & DiClemente) describes five stages: pre-contemplation (not thinking about change), contemplation (ambivalent), preparation (intending to act soon), action (actively changing), and maintenance (sustaining the change). Intervention should match the patient's stage; pushing an action-stage intervention on a pre-contemplator generates resistance.

Motivational Interviewing (MI), developed by Miller and Rollnick, is a collaborative, person-centred counselling style designed to evoke intrinsic motivation for change. Core principles are expressed via the acronym RULE: Resist the righting reflex (suppress the impulse to correct the patient), Understand patient motivation, Listen with empathy, and Empower the patient. Key MI skills are OARS: Open questions, Affirmations, Reflective listening, Summaries. The clinician listens for "change talk" — statements indicating desire, ability, reasons, or need for change — and gently reinforces these while rolling with resistance rather than confronting it.

The Health Belief Model posits that a person will take health action if they perceive: (1) susceptibility to a condition, (2) severity of that condition, (3) benefits of the action outweighing (4) barriers to taking it. A cue to action (e.g., a symptom or media campaign) may trigger action, and self-efficacy (confidence in one's ability to act) moderates the whole process.

Treatment adherence (sometimes called compliance, though this term is now disfavoured for implying passivity) is suboptimal across virtually all chronic conditions — approximately 50% of patients with chronic diseases take medications as prescribed. Factors predicting non-adherence include: complex regimens, side effects, asymptomatic conditions (e.g., hypertension), poor health literacy, cost, and lack of perceived benefit. Concordance — a shared decision-making approach where prescriber and patient agree on a treatment plan — is associated with better outcomes than prescribing without discussion.

Stress and coping: the Lazarus transactional model distinguishes primary appraisal (is this stressful?) from secondary appraisal (can I cope?). Coping strategies are classified as problem-focused (addressing the stressor directly) versus emotion-focused (managing the emotional response). Neither is universally superior; the optimal strategy depends on whether the stressor is controllable. Social support is a critical buffer, with strong evidence linking social isolation to worse health outcomes, including a 29% increased risk of cardiovascular disease.

HUMAN DEVELOPMENT — FIRST 1000 DAYS

The "first 1000 days" (conception to age two) represent a critical developmental window. The Developmental Origins of Health and Disease (DOHaD) hypothesis proposes that adverse exposures during this period — including maternal malnutrition, smoking, stress, and substance use — programme metabolic and neurological systems with consequences persisting into adult life, including increased risk of type 2 diabetes, cardiovascular disease, and mental health disorders. Secure attachment in infancy (Bowlby's attachment theory) predicts later emotional regulation, relationship quality, and resilience to stress.