ICD-10 Classification of Mental and Behavioural Disorders, World Health Organization, Geneva, 1992
Definition | Diagnostic Guidelines | DCR-10 Criteria
An uncommon disorder in which there is an insidious but progressive development of oddities of conduct, inability to meet the demands of society, and decline in total performance. Delusions and hallucinations are not evident, and the disorder is less obviously psychotic than the hebephrenic, paranoid, and catatonic subtypes of schizophrenia. The characteristic "negative" features of residual schizophrenia (e.g. blunting of affect, loss of volition) develop without being preceded by any overt psychotic symptoms. With increasing social impoverishment, vagrancy may ensue and the individual may then become self-absorbed, idle, and aimless. Simple schizophrenia is a difficult diagnosis to make with any confidence because it depends on establishing the slowly progressive development of the characteristic "negative" symptoms of residual schizophrenia without any history of hallucinations, delusions, or other manifestations of an earlier psychotic episode, and with significant changes in personal behaviour, manifest as a marked loss of interest, idleness, and social withdrawal.
ICD-10 copyright © 1992 by World Health Organization.