4.1.6 Disorders of self

Components of the sense of self

Ownership is experiencing a thought as one's own, while agency is producing or controlling it.

Depersonalisation and derealisation

• Depersonalisation is an unpleasant "as if" feeling of unreality or detachment from the self, including emotional numbing, with insight and reality testing kept.

• Derealisation is the same felt unreality applied to the surroundings, which seem distant, flat or artificial although the person knows they have not changed.

• An illusion misidentifies a stimulus, whereas derealisation changes how the stimulus feels.

• Depersonalisation is common and non-specific: it occurs in healthy people with fear, fatigue or sleep loss, and across many psychiatric disorders.

• Pathological depersonalisation differs from the transient kind in healthy people by the intense, distressing affect that comes with it.

• The neural basis is distributed, with prefrontal regions over-inhibiting insular and limbic emotional responses.

• Persistent or recurrent distressing episodes may meet criteria for depersonalisation-derealisation disorder once other causes are excluded.

Identity, continuity and dissociation

• Dissociative fugue starts abruptly after stress; consciousness stays clear, behaviour stays purposeful, and recovery is spontaneous, with amnesia for the fugue period afterwards.

• In fugue, general knowledge, learned skills and new learning are preserved, and neurological and substance-related causes must be excluded.

• Borderline personality disorder gives a long-standing unstable self-image and emptiness, which is not the same as distinct dissociative states.

• Bleuler's "schizophrenia" meant fragmentation of psychic functions, not split personality.

Thought alienation

Thought alienation is a loss of ownership of a thought, which is attributed to an external agent; it is not a disorder of the form or flow of thought.

• Thought broadcasting is a loss of the privacy of thought, with ownership kept.

• Ask how others come to know the thoughts, because direct transmission differs from inferring it from other people's expressions.

• Thought blocking is the objective, abrupt stop in the stream of thought, often mid-sentence, which the patient may explain delusionally as thought withdrawal.

Passivity experiences

The passivity group of first-rank symptoms covers body, feeling and will, and is separate from thought alienation.

• Somatic passivity differs from a plain somatic hallucination, which is a bodily sensation with no stimulus and no external attribution.

• A delusion of control is the explicit belief that one's thoughts, feelings or acts are directed from outside.

• Passivity experiences are a disturbance of self-agency and point to schizophrenia rather than delusional disorder.

Models of passivity and delusion

• The comparator (forward) model explains passivity of movement: the efference copy fails to predict the sensory consequences of one's own action, so self-made movement is not tagged as self-generated.

• The comparator model does not explain every delusion of control.

• The two-factor theory of monothematic delusions holds that an anomalous experience from a neuropsychological deficit (the first factor) becomes a held delusion only with impaired belief evaluation (the second factor).

• Misattribution of inner speech is one model of voice hearing.

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Delusional perception

• Delusional perception has two stages: a real object is perceived normally and accurately, then it suddenly takes on a delusional meaning with no understandable link to it.

• The abnormality lies in the meaning, not the percept.

• It is a primary delusion in Jaspers' sense, not understandable from the person's mood or circumstances, and it sometimes follows delusional mood.

Delusional perception is told apart from delusion of reference, which is not a first-rank symptom; from delusional mood, in which no percept has yet arrived; and from autochthonous delusion, which arises with no percept.

Klaus Conrad described the stages of beginning schizophrenia:

Schneider's first-rank symptoms

• Thought blocking, formal thought disorder, catatonic motor signs and non-specific delusions such as delusions of reference are not first-rank symptoms.

• First-rank symptoms are traditionally read as a breakdown of the ego boundary between self and outside world.

• Loss of ego boundaries held with conviction and with lost reality testing points to schizophrenia rather than borderline personality disorder.

• First-rank symptoms are suggestive but not specific: they occur in mania and in mood, substance-related and organic psychoses, so the whole picture decides the diagnosis.

• They are neither necessary nor sufficient, and modern criteria no longer give one in isolation special diagnostic status.

• Somatic passivity has relatively discriminating value for schizophrenia, unlike non-specific symptoms.

• First-rank symptoms are a diagnostic aid only and give no guide to severity, relapse or long-term outcome.

Self-world boundary

• People may describe merging with others or difficulty telling internal from external experience, which can occur in psychosis.

• Ecstasy is a state of extreme wellbeing in which the self-world boundary is altered and the change feels voluntary; it is not necessarily pathological.

• Ecstatic union occurs in accepted spiritual practice, mania or seizures, and its significance depends on context, control, associated symptoms and impairment.

Body schema and body image

• Body schema is the largely unconscious representation of the body used for action, while body image is its conscious representation.

• Paraschemazia is a disturbance of body schema in which the felt shape, alignment or attachment of body parts is distorted, twisted or split away.

• In paraschemazia the patient recognises that the feeling does not match reality, unlike a dysmorphic delusion; it occurs with hallucinogens, epileptic aura and, rarely, migraine.

• Paraschemazia is distinct from hyperschemazia, hyposchemazia, aschemazia and asomatognosia.

• Phantom limb is a disturbance of body image, not a somatic hallucination, because a peripheral nerve block reversibly abolishes it.

• Phantom limb pain is felt within the absent part, starts soon after surgery and is more likely after long-standing pain in the limb before amputation.

• Stump pain, by contrast, is confined to the scar.

Contexts and differentials

• Establish whether something merely feels changed or is believed to have changed literally, and record the person's words, conviction and insight.

• Brief recurrent stereotyped episodes suggest seizures, and unilateral symptoms or neglect suggest focal neurological disease.