Assessing positive and negative symptoms in outpatients with schizophrenia and mood disorders.

The Positive and Negative Syndrome Scale (PANSS) was developed to assess symptomatology in inpatients with schizophrenia. We examined its reliability and validity among outpatients with schizophrenia (N = 75) and mood disorders (N = 61). Because the hypothesized three-scale structure of the PANSS has not been supported by existing research, we also examined its factor structure. Interrater reliability for individual items and the positive and negative scales was demonstrated. Evidence supported the internal consistency of each scale in the overall sample and the schizophrenia group but was mixed among those with mood disorders. PANSS scores were higher in the schizophrenia group. These scores, in turn, were lower than those generally reported among inpatients with schizophrenia, providing known-groups validity evidence. Four of five factors were similar to those reported among inpatients with schizophrenia. Together, these results support the use of the PANSS among outpatients and reinforce existing support for assessing positive and negative symptoms in mood disorders.