Approach to the Diagnosis of Schizoaffective Disorder

Abstract

Diagnosing schizoaffective disorder poses unique challenges due to both its history as a “catch-all” diagnosis and recent changes to the diagnostic criteria. The Diagnostic and Statistical Manual of Mental Disorder s, fifth edition, helps to clarify the diagnosis, but issues related to validity and reliability remain. The fundamental approach to diagnosis must be done positively (as opposed to being a diagnosis of exclusion), looking at each feature of a patient's presentation and ensuring that criteria for schizoaffective disorder are met, without symptoms being better explained by a phenomenologically similar yet different psychiatric conditions (and assuming that no medical or toxic condition is responsible). This article presents a straightforward approach to generating and critically assessing a differential diagnosis when schizoaffective disorder is suspected. [ Psychiatr Ann . 2020;50(5):195–199.]