Is schizoaffective disorder a stable diagnostic category: a retrospective examination.

Debate continues about whether clear nosologic boundaries can be drawn between schizoaffective disorder (SA), schizophrenia (SP), and bipolar disorder (BPD). This study attempted to clarify these boundaries. A retrospective review of the records of adult psychiatric inpatients with DSM-IV diagnoses of SA (n = 96), SP (n = 245), and BPD (n = 203) was conducted. Patients were assessed at admission and discharge using standardized rating scales (completed by physicians and nurses) and self-report inventories. Differential improvement over time also was examined. Significant differences were found for gender, legal status at admission, age, LOS, episode number, and ethnicity. Overall, SA was rated by clinicians as intermediate between SP and BPD, although SA rated themselves as the most severe. SA was similar to SP on positive symptoms, intermediate on negative symptoms, and similar to BPD on mood- and distress-related symptoms. Independent of diagnosis, differences in change scores from admission to discharge were related to severity level at admission. Although several differences were found in symptom severity across domains, no syndrome was identifiable associated with the diagnosis of SA and the diagnosis was unstable over time, thereby bringing into question the validity of SA as a diagnostic entity.