Validity of subtyping psychotic depression: examination of phenomenology and demographic characteristics.

The authors examine the validity of subtyping psychotic depression by comparing 111 patients with schizoaffective, unipolar, and bipolar psychotic depression on demographic characteristics and symptoms at index episode. Diagnoses were made by using Research Diagnostic Criteria (RDC). The three groups were indistinguishable in sex, race, and age at onset. Schizoaffective patients had more "schizophrenic" symptoms but were not different in depressive delusions, other psychotic symptoms, or affective symptoms. However, bipolar patients scored significantly higher than nonbipolar patients on hypomania. There is little support in these data for the schizoaffective versus nonschizoaffective distinction. Further tests are needed, including tests of response to treatment and biological markers.