Objectives:
The aim of the present study was twofold: 1. to compare the efficacy of three antipsychotics (ziprasidone, olanzapine and perazine) in schizophrenia 2. to compare the improvement in cognitive functioning between groups treated with the three different neuroleptics.

Methods:
A total of 58 Caucasian patients diagnosed with paranoid schizophrenia were recruited into the study group. We used the Polish version of the CIDI (Composite International Diagnostic Interview) to obtain ICD-10 diagnoses. The intensity of psychopathological symptoms was examined using the PANSS. The patients were randomly assigned to treatment with perazine, olanzapine or ziprasidone administered as monotherapy for 3 months. The treatment efficacy was measured as a change in the PANSS (Positive and Negative Syndrome Scale) total score from baseline (T0) to 3 months (T1). The WCST (The Wisconsin Card Sorting Test) was used to measure working memory and executive functions in the evaluated patients. Wilcoxon’s and Kruskal-Wallis tests were used to compare changes in the PANSS scores between the treatment groups. To analyze the cognitive functions, we used Kruskal-Wallis test for the WCST parameters.

Results:
The three antipsychotics similarly reduced the total PANSS score. The WCST parameters in the 3 groups of examined patients using the Kruskal-Wallis test revealed some differences between the three administered antipsychotics.

Conclusions:
Results suggest that the short-term efficacy of the atypical (olanzapine, ziprasidone) and typical (perazine) antipsychotic drugs did not differ. Based on the analysis, a conclusion can be drawn that the three neuroleptics provided similar improvements in cognitive functioning.