Bipolar disorder, schizoaffective disorder and schizophrenia: epidemiologic, clinical and prognostic differences

The validity and nosologic status of schizoaffective disorder is still a co ntroversial issue. This study was conducted to analyze the demographic, cli nical and prognostic variables that determine the validity of the diagnosis of schizoaffective disorder bipolar type. We analyzed and compared 138 out patients: 67 with type I bipolar disorder, 34 with schizoaffective disorder bipolar type and 37 with schizophrenia. They were all diagnosed following research diagnostic criteria and assessed according to the Schedule for Aff ective Disorders and Schizophrenia. Schizoaffective unipolar patients were excluded. The results reaffirmed that, from the standpoints of demographics , clinical features and prognosis, schizoaffective disorders bipolar type c an be classified as a phenotypic form at an intermediate point between bipo lar I disorder and schizophrenia. These results emphasize the importance of longitudinal follow-up in the diagnosis and assessment of psychotic syndro mes. Although cross-sectional symptoms were closer to the schizophrenia spe ctrum, the course of the illness resembled more that of bipolar patients, r esulting in an intermediate outcome. (C) 2001 Editions scientifiques et med icales Elsevier SAS.