ARE POSITIVE AND NEGATIVE SYMPTOMS RELEVANT TO CROSS-SECTIONAL DIAGNOSIS OF SCHIZOPHRENIC AND SCHIZOAFFECTIVE PATIENTS

The value of positive and negative symptoms for cross-sectional differ ential diagnosis was studied in a sample of 103 consecutively admitted patients with schizophrenia and schizoaffective psychoses. A semistru ctured interview for schizophrenia was used. Subjects were diagnosed b y Research Diagnostic Criteria (RDC) and classified as schizophrenic, depressive schizoaffective, and manic schizoaffective disorders. DSM-I II-R criteria for schizophrenia were used to assign RDC schizophrenics to two groups: ''true'' schizophrenic (fulfilling both DSM-III-R and RDC criteria) and schizophreniform (fulfilling RDC but not DSM-III-R c riteria). The Scale for the Assessment of Positive Symptoms (SAPS) and Scale for the Assessment of Negative Symptoms (SANS) were used. Our f indings showed that both positive and negative symptoms were relevant to differential diagnosis between schizophrenia and other psychotic di sorders. However, negative symptoms presented higher significant diffe rences between diagnostic groups than positive symptoms.