Purpose of review
Schizoaffective disorder was named as a compromise diagnosis in 1933, and remains popular as judged by its place in the International Classification of Diseases and the Diagnostic and Statistical Manual of Mental Disorders, its frequent use in clinical practice, and its extensive discussion in the literature. Some, however, have questioned the validity of schizoaffective disorder as separate from psychotic mood disorder. We examined the literature to assess the rationale for the continuation of schizoaffective disorder as a legitimate diagnostic category.
The diagnosis of schizoaffective disorder depends on the disease specificity of the diagnostic criteria for schizophrenia; however, the psychotic symptoms for schizophrenia, traditionally held as specific, can be accounted for by psychotic bipolar. Further, the interrater reliability for diagnosing schizoaffective disorder is very low. A recent and expanding body of comparative evidence from a wide range of clinical and basic science studies, especially genetic, reveals multiple similarities between schizoaffective disorder, schizophrenia and psychotic bipolar.
Schizoaffective disorder unifies schizophrenia and bipolar, blurring the zones of rarity between them and suggesting that schizoaffective disorder is not a separate, ‘bona-fide’ disease. Patients diagnosed with schizoaffective disorder likely suffer from a psychotic mood disorder. The diagnosis of schizoaffective disorder, which can result in substandard treatment, should be eliminated from the diagnostic nomenclature.