How Well Does the DSM-5 Capture Schizoaffective Disorder?

Schizoaffective disorder has long been recognized and quite variably defined. It has been variably positioned as a discrete entity, a variant of either schizophrenia or of a mood disorder, as simply reflecting the co-occurrence of schizophrenia and a mood disorder, and effectively reflecting a diagnosis along a continuum linking schizophrenia and bipolar disorder. This article considers historical views, some empirical data that advance consideration of its status, and focuses on its classification in the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5). DSM-5 criteria seemingly weight it in the direction of a schizophrenic illness, as do some empirical studies, whereas the empirical literature examining the response to lithium links it more closely to bipolar disorder. It is suggested that DSM-5's B and C criteria are operationally unfeasible. Some suggestions are provided for a simpler definition.