The effect of typical neuroleptics and atypical antipsychotics on working memory in schizophrenic patients

There are numerous reports on beneficial effect of atypical antipsychotics on cognitive process in schizophrenic patients. Unlike, few studies concerning typical neuroleptics were undertaken. The dorsolateral prefrontal cortex is responsible for adequate functioning of working memory, which plays essential role in cognitive functioning. Working memory is associated with including new informations into those actually processed, plasticity of thinking and school and job functioning. Purpose: This study was undertaken to compare influence of typical neuroleptics and atypical antipsychotics on working memory in schizophrenic outpatients. Furthermore, one tried to establish, which of indices of WCST correlates with TMT B. Material: The study included 62 outpatients (some recently discharged from the hospital) with schizophrenia diagnosed according to the ICD-10 criteria. All patients were divided into two 31-subject groups. They were carefully matched in pairs according to age, gender, place of living, and level of education. The patients in one group were treated with typical neuroleptics and in the other with atypical antipsychotics. Methods: WCST and TMT (A and B version) were used. Correlation between the results of TMT B version and each of 7 WCST indices were evaluated. Results: No statistically significant difference was observed between the two groups in all WCST indices results. Also TMT results in both groups did not differ significantly. Only a weak negative correlation was recorded between TMT B version and the WCST index – Learning to Learn. Conclusions: Functioning of working memory was similar in the patients on either typical neuroleptics and atypical antipsychotics.