Dissociative and Somatic Symptom Disorders — Conversion, Somatisation, Illness Anxiety and Dissociation

These disorders share one feature: psychological distress is expressed as physical symptoms or altered consciousness, memory or identity without a medical explanation that accounts for the picture. The two classification systems group them differently, which is a favourite source of exam confusion.

Dissociation is defined in DSM-5 as a disruption or discontinuity in the normal integration of consciousness, memory, identity, emotion, perception, body representation, motor control and behaviour. ICD-10 describes dissociative disorders as a partial or complete loss of the normal integration between memories of the past, awareness of identity and immediate sensations, and control of bodily movements. Both systems recognise that these disorders have physical as well as psychological symptoms, and ICD-10 can diagnose them only when there is a clear association in time with a stressful event or problem, even if the patient denies it.

Somatic symptom disorder (SSD) involves one or more physical symptoms with excessive thoughts, emotions or behaviours about them that cause significant distress or dysfunction. The physical symptoms may or may not be explained by a medical condition — a key DSM-5 change was removing the requirement that symptoms be 'medically unexplained'. The diagnosis rests on the excessive psychological response, not on the symptom itself.

1. One or more persistent somatic symptoms that cause significant distress or disruption of daily life.
2. Excessive and persistent thoughts, feelings or behaviours related to the symptoms — at least one of: disproportionate and persistent thoughts about seriousness; persistently high anxiety about health or symptoms; excessive time and energy devoted to symptoms.
3. Duration more than 6 months (symptoms may be intermittent; one symptom, often pain, may predominate).

Management aims to help the patient cope with symptoms, health anxiety and maladaptive behaviours, not to eliminate every symptom. StatPearls describes stepped care: (1) a strong therapeutic relationship with regular, time-limited scheduled visits rather than symptom-driven ones; (2) limited but adequate testing — excess tests risk false positives and reinforce the cycle; (3) a shared biopsychosocial explanation; (4) cognitive behavioural therapy (CBT), the psychotherapy with the strongest evidence; (5) adjunctive SSRIs or SNRIs, started at the lowest dose and increased slowly because these patients readily perceive side effects. Avoid benzodiazepines and opioids.

Illness anxiety disorder (IAD) was called hypochondriasis in DSM-IV. The patient has few somatic symptoms, if any, but a preoccupation with having or acquiring a serious illness, with excessive health-related behaviours (repeated self-checking for signs of disease) or maladaptive avoidance (skipping doctor visits or hospitals). In SSD the symptoms are prominent; in IAD the fear is prominent.

SSD can also be confused with generalised anxiety disorder (worry about many things, not just symptoms), major depression with somatic features (core depressive symptoms are present), panic disorder (symptoms occur in discrete attacks) and delusional disorder, somatic type (the belief is fixed at delusional intensity). A medical diagnosis does not exclude SSD, and SSD does not exclude a real medical illness.

Functional neurologic disorder (FND), the DSM-5 name for conversion disorder, produces motor or sensory symptoms that do not fit recognised neurological disease. It is classed with the somatic symptom and related disorders in DSM-5-TR. Earlier DSM editions required a clear psychological stressor and proof that symptoms were not intentionally produced; DSM-5 dropped both requirements and also removed 'la belle indifférence' (apparent indifference to the deficit) as a diagnostic criterion — it is now only a supportive feature. Symptoms lasting less than 6 months are acute; more than 6 months is persistent; the specifier 'with or without psychological stressor' is available.

• Hoover's sign (functional leg weakness) — per the Indian emergency guideline, the patient lies supine, the examiner places a hand under the heel of the non-paralysed leg and asks the patient to lift the paralysed leg. Downward pressure from the non-paralysed leg means the sign is negative (organic); no pressure from the non-paralysed leg means the sign is positive, indicating a dissociative (functional) cause.
• Abductor sign — the examiner applies adducting pressure on both legs while the patient abducts the non-paralysed leg; a functional (dissociative) weakness is suggested if the paralysed leg stays in the same position.
• Functional tremor — abrupt onset, present at rest and with action, fluctuating frequency, often triggered by an emotional event, and the amplitude generally increases when weights are added to the limb, unlike organic tremor.
• Functional blindness — the pupillary light reflex is present; true blindness would cause difficulty moving around and bruising.

In India dissociative disorders are common in emergency and psychiatric outpatient practice. One psychiatric-institute review reported the commonest outpatient diagnosis as dissociative motor disorder (43.3%), then dissociative convulsions (23.0%) and trance and possession disorder (11.5%), with dissociative stupor 6.6%, dissociative amnesia 4.1%, and dissociative fugue only 1.4%. Dissociative amnesia and fugue are therefore uncommon in practice despite being popular in exams, and dissociative identity disorder is very rare in emergencies.

DID was called multiple personality disorder until 1994. DSM-5 criteria require two or more distinct personalities, each with its own pattern of behaviour, sense of consciousness, memory and perception of the outside world, with recurrent gaps in memory for everyday and traumatic events. The symptoms must not be due to substances or cultural practice and must cause functional impairment. Estimated prevalence is about 1 to 1.5% of the population.

• Cause — typically severe childhood trauma and abuse (physical, emotional or sexual). The theory of Putnam suggests that traumatised children, especially if exposed before age 5, fail to develop a unified sense of self.
• Onset — unlike other dissociative disorders (late adolescence to early adulthood), DID begins in early childhood; male and female frequencies are about equal.
• 'Switches' between alters may show as trance-like behaviour, eye blinking or rolling and change in posture.
• Diagnosis — detailed longitudinal history from several sources; screening with the Dissociative Experiences Scale (28 items). Rule out autoimmune encephalitis and other neurological causes.
• Misdiagnosis — most often as borderline personality disorder; alters may be mistaken for hallucinations and treated as schizophrenia.

Treatment uses a three-phase approach: (1) safety, stabilisation and symptom reduction (suicidal ideation and self-injury are common); (2) processing and integrating traumatic memories; (3) identity integration and rehabilitation. The core is psychotherapy; hypnosis and EMDR (once the patient is stable) are used within integrative treatment. No medication has been found effective for DID itself — drugs are used for comorbid mood, PTSD or anxiety symptoms.

1. Establish safety — remain calm, move the patient to a quiet room, remove bystanders unless needed, keep the area free of sharps, and monitor airway, breathing and circulation in a convulsion.
2. Avoid noxious stimuli (ether inhalation, sternal pressure) in a stuporous patient.
3. Relaxation and grounding — slow deep breathing, calm instructions, orienting the patient to name, date and place; focusing on a sound, a palm-sized object or naming colours in the room.
4. Medication only if needed — for acute anxiety or agitation, lorazepam 2 mg or clonazepam 0.5 mg orally; lorazepam 2 mg IM or IV can be repeated after 30 minutes. Severe psychotic-type agitation: IM haloperidol up to 5 mg with promethazine 25 mg. No psychotropic is specifically recommended for dissociative disorders.
5. Build rapport with patient and family and address the underlying stressors; CBT is the best-supported psychotherapy for functional neurological symptoms.

• Classification — conversion disorder is dissociative in ICD-10 but somatic symptom-related in DSM-5.
• SSD — symptoms for more than 6 months plus excessive thoughts, feelings or behaviours; DSM-5 no longer needs 'medically unexplained'; best psychotherapy is CBT.
• IAD — little or no somatic symptoms, preoccupation with disease; formerly hypochondriasis.
• Conversion — Hoover's sign; la belle indifférence is not required for diagnosis; commonest subtype is PNES; CBT and physiotherapy.
• Factitious vs malingering — sick role without reward vs external gain.
• Dissociative — fugue = amnesia + travel; DID = childhood trauma, phased psychotherapy, no drug treatment; commonest Indian presentations are motor symptoms and convulsions.