Cognitive dysfunctions are core and enduring deficits in schizophrenia, existed before first episode of the illness. Novel antipsychotic drugs exert more favourable influence on the cognitive performance in schizophrenia, compared with typical neuroleptics. However, some differences in this respect between various atypical antipsychotics may exist. In our study risperidone treatment resulted in significant amelioration of performance on all neuropsychological tests both after short- and long-term treatment. Olanzapine gave benefit on selected tests, although in most instances, this effect was noted only after long-term treatment. Olanzapine was inferior to risperidone in improving WCST performance. Treatment with phenothiazine’s brought about improvement on two subtests while the results on three showed significant deterioration. The results obtained suggest that novel antipsychotics show differential effect on cognition, with risperidone especially improving working memory; however, they have superior influence on negative symptoms and cognitive functions compared to phenothiazines.
Improvement of cognitive functions in patients with schizophrenia during treatment with atypical neuroleptics may result in improvement of compliance, problem solving, better social adaptation and improvement of quality of their life.