Somatisation

Overview

Distinguishing somatisation disorder from conversion disorder and illness anxiety disorder is the core exam skill for this topic.

Somatisation disorder vs conversion disorder vs illness anxiety disorder
FeatureSomatisation disorderConversion disorderIllness anxiety disorder (hypochondriasis)
SymptomsMultiple, across multiple organ systems (pain, GI, neurological, sexual)Single focal neurological deficit (e.g. numbness, weakness, paralysis)Few or no physical symptoms; preoccupation with having a serious illness
DurationProlonged - months to years, onset before age 30Acute onset, often precipitated by an identifiable psychological stressorPersistent health worry despite negative investigations
Key exam clueMany unexplained complaints across many systems over many yearsNon-dermatomal or anatomically inconsistent deficit + recent stressorReassurance-seeking; remains convinced of serious illness despite normal results

Feature	Somatisation disorder	Conversion disorder	Illness anxiety disorder (hypochondriasis)
Symptoms	Multiple, across multiple organ systems (pain, GI, neurological, sexual)	Single focal neurological deficit (e.g. numbness, weakness, paralysis)	Few or no physical symptoms; preoccupation with having a serious illness
Duration	Prolonged - months to years, onset before age 30	Acute onset, often precipitated by an identifiable psychological stressor	Persistent health worry despite negative investigations
Key exam clue	Many unexplained complaints across many systems over many years	Non-dermatomal or anatomically inconsistent deficit + recent stressor	Reassurance-seeking; remains convinced of serious illness despite normal results

🎯
A single focal neurological symptom (e.g. unilateral numbness in a non-dermatomal distribution) in the context of an acute psychological stressor = conversion disorder, NOT somatisation disorder. Somatisation disorder requires multiple symptoms across multiple systems over a prolonged period.

Management

🥇 First-line

•Psychoeducation and reattribution model - validate distress, introduce mind-body link without dismissing symptoms; consistent named GP with scheduled (not on-demand) appointments

•Cognitive behavioural therapy (CBT) - most evidence-based psychological intervention; targets illness beliefs, catastrophic cognition, and avoidance

•Treat comorbid depression/anxiety - sertraline (SSRI) has evidence for improving functional outcomes even without a formal depressive diagnosis

🥈 Second-line

•Mindfulness-based cognitive therapy; graded activity and physiotherapy for deconditioning

🥉 Third-line

•Specialist liaison psychiatry or multidisciplinary pain/fatigue clinic for refractory cases

⚠️
Avoid over-investigation - it reinforces illness behaviour and causes iatrogenic harm. However, do not attribute every new symptom to somatisation; organic pathology and functional illness can co-exist.

Presentation - Somatisation Disorder

•Multiple, recurring somatic complaints spanning different organ systems - frequent attender, repeated negative investigations

•Pain - most common symptom; head, abdomen, back, joints, or chest

•GI symptoms - nausea, bloating, diarrhoea, vomiting

•Neurological symptoms - dizziness, paraesthesia, memory difficulties (focal deficits point more to conversion disorder)

•Sexual/reproductive symptoms - dyspareunia, menstrual irregularities

•Comorbid depression and anxiety - present in the majority; screen actively