Positive and negative symptoms in schizophrenia

Negative and positive symptoms were determined for 46 drug-free patients who met Research Diagnostic Criteria (RDC) and/or Feighner criteria for schizophrenia. A modified version of the Scale for the Assessment of Negative Symptoms (SANS) was completed for each patient based on items from the Schedule for Affective Disorders and Schizophrenia (SADS) and other scales. Positive symptoms were scored from the SADS as well as from the following four diagnostic systems: RDC, Schneider's first-rank symptoms, the 12-point Flexible system, and Langfeldt's criteria for poor prognosis schizophrenia. For all patients, there was no correlation of negative symptoms and positive symptoms defined by any diagnostic system. Within the paranoid and undifferentiated subtypes, there was a positive correlation of positive and negative symptoms. Patients moving from stable to exacerbated states had an increase in both positive and negative symptoms, and patients with a poor history of treatment response had both more positive and more negative symptoms than responsive patients in a stable state. These results do not support the view that subgroups of patients have predominantly either negative or positive symptoms.