Schizoaffective disorder
Schizoaffective disorder is a specialist psychotic disorder in which schizophrenia symptoms and a clinically significant mood episode occur in the same illness; diagnosis depends on the classification system and a reliable time course, so psychosis, mood, risk, medical causes and treatment response must all be assessed longitudinally.
Definition
Schizoaffective disorder is a primary psychotic disorder in which the diagnostic requirements for schizophrenia and a moderate or severe depressive, manic or mixed episode are met concurrently. Under current WHO ICD-11 clinical descriptions, the psychotic and mood symptoms begin simultaneously or within a few days and persist for at least 1 month. DSM-5 uses a different longitudinal formulation, including at least 2 weeks of delusions or hallucinations without a major mood episode; the classification system must therefore be stated.
First principles
The diagnosis is about both domains and their timing
The person has characteristic psychotic symptoms such as delusions, hallucinations, disorganised thinking or behaviour, together with a moderate or severe depressive, manic or mixed episode. Current WHO ICD-11 diagnostic requirements describe schizophrenia symptoms and mood symptoms occurring concurrently, with onset at the same time or within a few days and lasting at least 1 month. The often-taught requirement for at least 2 weeks of psychosis without a major mood episode is the DSM-5 formulation, not the current ICD-11 requirement; do not mix criteria without naming the classification being used.
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