ICD-11

Schizophrenia is characterised by disturbances in multiple mental modalities, including thinking (e.g., delusions, disorganisation in the form of thought), perception (e.g., hallucinations), self-experience (e.g., the experience that one's feelings, impulses, thoughts, or behaviour are under the control of an external force), cognition (e.g., impaired attention, verbal memory, and social cognition), volition (e.g., loss of motivation), affect (e.g., blunted emotional expression), and behaviour (e.g., behaviour that appears bizarre or purposeless, unpredictable or inappropriate emotional responses that interfere with the organisation of behaviour). Psychomotor disturbances, including catatonia, may be present. Persistent delusions, persistent hallucinations, thought disorder, and experiences of influence, passivity, or control are considered core symptoms. Symptoms must have persisted for at least one month in order for a diagnosis of schizophrenia to be assigned. The symptoms are not a manifestation of another health condition (e.g., a brain tumour) and are not due to the effect of a substance or medication on the central nervous system (e.g., corticosteroids), including withdrawal (e.g., alcohol withdrawal).

Schizophrenia, multiple episodes should be used to identify individuals experiencing symptoms that meet the diagnostic requirements for Schizophrenia and who have also previously experienced episodes during which diagnostic requirements were met, with substantial remission of symptoms between episodes. Some attenuated symptoms may remain during periods of remission, and remissions may have occurred in response to medication or other treatment.

All definitional requirements for Schizophrenia, multiple episodes in terms of symptoms and duration were previously met. Symptoms have ameliorated such that the diagnostic requirements for the disorder have not been met for at least one month, but some clinically significant symptoms remain, which may or may not be associated with functional impairment. The partial remission may have occurred in response to medication or other treatment.