The impact of typical and atypical anti-psychotics on developing obsessive-compulsive symptoms in schizophrenic patients were investigated in this study.

64 schizophrenic patients (32 cases in typical anti-psychotics group and 32 in atypical anti-psychotics group) participated in the study. All the patients first interviewed by SCID and then Yale Brown Obsessive-Compulsive Scale (Y-BOCS) and Brief psychiatric Rating Scale were administered in the beginning, 3 weeks and 6 weeks after treatment. The Data then transferred to SPSS program. for analysis.

In typical group the mean scores of Y-BOCS were 2.40, 2.30 and 2.18 in the beginning, 3 weeks and 6 weeks after treatment. In atypical group the mean scores of Y-BOCS were 4.12, 4.46 and 4.53 in three trials. There were no significant differences in the mean scores of Y-BOCS of two group in the beginning of the trial although a trend toward significance was observed but the differences between scores were significant in trial 2 (3 weeks) and trial 3 (6 weeks).

Based on this study and in line with previous studies, atypical anti-psychotics may induce obsessive compulsive symptoms (although mild) in patients with schizophrenia.