"Schizoaffective disorder": an invalid diagnosis? A comparison of schizoaffective disorder, schizophrenia, and affective disorder

Abstract

Patients meeting widely accepted criteria for the diagnosis of schizoaffective disorder, manic type, were compared with patients meeting rigorous criteria for manic disorder and schizophrenia, using 3 methods of validation: family history, short-term treatment response and long-term outcome. No significant differences were found between patients with manic disorder and schizoaffective disorder. Consistent and often highly significant differences separated patients with schizophrenia from those with manic disorder and schizoaffective disorder. Apparently schizoaffective disorder, as currently defined, is not a valid and independent entity. Apparently psychotic disorders not diagnosable as manic-depressive illness or schizophrenia and without apparent organic basis would best be called undiagnosed or atypical psychosis. While proposals for new diagnoses or for subtyping of schizophrenia or manic-depressive illness should be encouraged, these should undergo rigorous screening for validity before being accepted into clinical use.