A neuropsychological study of prefrontal lobe function in the positive and negative subtypes of schizophrenia

The symptoms of schizophrenia are frequently divided into positive and negative subtypes. It has been suggested that the negative symptoms are similar to those seen with prefrontal lobe cortical dysfunction. Several neuropsychological investigations of that hypothesis have been carried out, but none have directly compared a negative symptom group with a positive symptom group on the same test battery. In the present study, the Positive and Negative Syndrome Scale (PANSS; Kay, Fiszbein, & Opler, 1987) was used to distinguish two groups of 20 patients with schizophrenia with predominant positive or negative symptoms. A battery of 7 neuropsychological tests considered capable of isolating prefrontal lobe dysfunction was administered. A significant group difference was noted on 6 of the tests; the negative symptom group performed much worse than the positive symptom group. The results of this study support the hypothesis that a relationship exists between the negative symptoms of schizophrenia and prefrontal lobe dysfunction.