The factor structure for the Positive and Negative Syndrome Scale (PANSS) in recent-onset psychosis

The Positive and Negative Syndrome Scale (PANSS) is a widely used instrument for measuring severe psychopathology in adult patients with schizophrenia. Data, primarily on chronic patients, have been used to define factors for the PANSS. The present study examines the PANSS factor structure in a large sample of subjects with recent-onset schizophrenia, schizophreniform disorder and schizoaffective disorder who had been exposed to very limited antipsychotic medication. Equamax factor analysis was conducted on PANSS baseline assessments from a multicenter, 11 country drug trial that enrolled 535 patients. The forced five-factor solution essentially corresponds to the factors most frequently described previously, namely negative, positive, disorganized (or cognitive), excited and anxiety/depression. In the exploratory analysis, a seven-factor solution was obtained, with depression and anxiety symptoms separating and a motor component emerging. The results of this study partially support the use of a five-factor model for the PANSS, but suggest that scales for catatonia, depressive and anxiety syndromes should be included in future studies.