From Big Medical Encyclopedia

DEREALIZATION (Latin the de-prefix decrease, extraction + realis material) — the disorder of mental activity which is expressed in feeling of unreality and extreneity to the patient of the real world surrounding it, one of forms of disturbance of consciousness. At D. objects, natural phenomena, people are perceived as alien, unreal, illusive, nonexistent, unnatural, artificial, changed, strange, vague, lost relief, pale, dim, lifeless («alienation of the world of perceptions»). Voices and sounds are deaf, alien, unreal, vague. Patients usually use the listed definitions, telling about the disease state. At the same time they often complain that they cannot put precisely into words what happens to them. Symptoms belong to derealizatsionny frustration: deja vu (already seen) when unfamiliar (objects, a surrounding situation, people), seen for the first time, it is perceived as already familiar, and jamais vu (never seen) when familiar is perceived as absolutely unfamiliar. At D. experience of time is broken, a cut it is perceived sick as stiffened, stopped, or the course of time seems too bystry, in other cases — slowed down. Much more rare at D. surrounding is perceived unnaturally accurate, bright, colourful (some authors speak in such cases about the superawake consciousness). At D. emotional disturbances in the form of feeling of melancholy, fear, alarm, emotional indifference, surprise, bewilderment, confusion, helplessness are observed. As a rule, at D. consciousness of the painful nature of the available frustration remains, and in some cases there is also rather full criticism. Usually patients with D. compare the real mental state with that, a cut was at them before emergence of this frustration.

Is often observed along with depersonalization (see); in these cases it is possible to speak about a depersonalizatsionno-derealizatsionny syndrome. Sometimes designate as allopsikhichesky depersonalization, emphasizing change of perception of the outside world while actually depersonalization is called still autopsikhichesky depersonalization, indicating by it change of consciousness, sense of reality of own personality.

Unlike hallucinations (see), D. is not imaginary perception; from illusions (see) it distinguishes existence of adequate assessment surrounding, despite experience of unreality; from Kandinsky's syndrome — Klerambo (see. Kandinsky-Klerambo syndrome ) — lack of the «perfection» created by foreign intervention, extreneity, lack of experience of influence from the outside.

Is observed at schizophrenia (see), at epilepsies (see) various genesis (during mental aura, an equivalent and during recovery of consciousness after an attack), vascular diseases, tumors and injuries of a brain, infections, in particular at epid, encephalitis (see). Often arises at intoxications drugs (hashish, opium, morphine), hypnotic drugs (barbiturates), in an initial stage of an insulin hypoglycemia and during the escaping it, at therapy by a long dream before final awakening. Various derealizatsionny frustration are caused by intoxication hallucinogens (a mescaline, diethyl amide lysergic to - you). Meets in a depressive phase of circular psychosis (see. Maniac-depressive psychosis ), at psychasthenias (see), exhaustion, somatogenic asteniye and incidentally at psychogenic reactions.

To treat the basic disease follows.

Predictive value It is inadequate: it can be a symptom of progreduated process (schizophrenia, epilepsy, organic diseases of a brain) and a symptom of a functional reversible disease (a circular depression, asthenic states).

Bibliography: Megrabyan A. A. Depersonalization, Yerevan, 1962, bibliogr.; Meerovich R. I. Frustration of «scheme» of a body at mental diseases, L., 1948, bibliogr.; Korkina M. V. The syndrome of derealisation in adolescence, in book: Modern perspectives in adolescent psychiatry, ed. by J. G. Howells, p. 329, Edinburgh, 1971, bibliogr.; ScharfetterCh. Allgemeine Psychopathologie, Stuttgart, 1976.

V. M. Morozov.