Definition and Diagnosis
Schizoaffective disorder is characterized by an uninterrupted period of illness during which a major mood episode (depressive or manic) occurs concurrently with symptoms meeting criteria for schizophrenia, along with a period of psychotic symptoms occurring in the absence of a mood episode.
Epidemiology
Schizoaffective disorder is less common than schizophrenia, with a lifetime prevalence estimated around 0.3%, and onset is typically in early adulthood.
Risk Factors
Risk factors overlap substantially with those for schizophrenia and mood disorders, including genetic predisposition, family history of either condition, and similar neurodevelopmental and environmental risk factors.
Symptoms and Subtypes
Features include psychotic symptoms such as hallucinations and delusions occurring alongside major depressive or manic episodes, with at least two weeks of psychotic symptoms occurring without a prominent mood episode at some point during the illness.
Diagnosis
DSM-5-TR requires an uninterrupted period of illness with a major mood episode concurrent with active-phase schizophrenia symptoms, delusions or hallucinations for two or more weeks in the absence of a major mood episode, and mood symptoms present for the majority of the illness duration.
Treatment
Treatment typically combines antipsychotic medication with mood stabilizers or antidepressants depending on the predominant mood component, alongside psychosocial interventions similar to those used in schizophrenia.
Prognosis
Prognosis is generally intermediate between schizophrenia and mood disorders alone, with course and outcome influenced by the severity and persistence of both psychotic and mood symptoms.
Reference
Sadock, B. J., Sadock, V. A., & Ruiz, P. Kaplan & Sadock's Synopsis of Psychiatry (11th ed.).