The Course Patterns and Diagnostic Shifts of Patients With Schizoaffective Disorder: A Retrospective Cohort Study.

Since its introduction, schizoaffective disorder (SAD) has been one of the most controversial diagnoses in psychiatry, both clinically and nosologically. In the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), SAD diagnostic criteria were changed, and instead of a cross-sectional diagnosis, a longitudinal approach covering the life course of the illness was adopted. In this study, the meaning of this conceptual shift in the diagnosis of SAD in clinical practice is investigated throughout the course of the illness for patients with SAD. Sixty-two inpatients diagnosed with SAD according to DSM-5 diagnostic criteria are included in this study. The course of the illness from its onset to the present is investigated retrospectively. The disease duration is 18.3 ± 9.1 years. The most common diagnoses in the first hospitalization are bipolar disorder (manic episodes) and psychotic disorder, not otherwise specified. Furthermore, the time that elapsed between the first psychiatric application of the patients and the diagnosis of SAD is 9.5 ± 7.3 years. Further, when the course of the illness is grouped according to the predominance of affective and psychotic disorders, recurrent affective disorders are observed most frequently (29.3%), followed by mixed-episode disorders and a shift from affective disorders to psychotic disorders (22.4%). It is found that SAD has a heterogeneous course, and affective disorder diagnoses are more dominant during the course of the illness. The clinical relevance of the longitudinal emphasis on the total duration of the illness in the DSM-5 is also demonstrated. The affective and psychotic dichotomy, based on Kraepelin, has failed to elucidate the course of the disease in clinical practice. Therefore, clinicians should meticulously evaluate the entire course of the illness for SAD and avoid conclusive judgments over a single episode.