Risperidone treatment of schizophrenia: improvement in psychopathology and neuropsychological tests.

The aim of the study was to assess the effects of short-term risperidone treatment on schizophrenic symptoms and on neuropsychological frontal tests, and to find an association between the improvements in these two kinds of domains. Twenty-two schizophrenic patients treated with risperidone (2-6 mg/day) for 4 weeks were studied. Treatment with risperidone resulted in a significant decrease in the intensity of schizophrenic symptoms and in an improvement in all neuropsychological tests applied. A robust correlation was obtained between the amelioration of negative symptoms and improvements in many neuropsychological tests, specifically with amelioration in the Wisconsin Card Sorting Test (WCST), perseverative errors. Some correlation was also found with the improvement of positive symptoms, specifically with amelioration in the WCST, completed categories. The results may suggest a common neurobiological substrate of negative and cognitive symptoms, reflected in prefrontal cortex pathology and in therapeutic response to atypical antipsychotics.