Objectives: The effects of typical and atypical antipsychotics on inducing obsessive-compulsive symptoms in patients with schizophrenia were compared in this study.

Method: In a comparative-descriptive study 64 patients with schizophrenia (32 patients in typical antipsychotic group and 32 patients in atypical antipsychotic group) were investigated. All patients with a confirmed diagnosis of schizophrenia based on Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I), underwent Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and Brief Psychiatric Rating Scale (BPRS) at the beginning, as well as three and six weeks after treatment. Data were analyzed using descriptive statistics, repeated measures analysis of variance, and t-test.

Results: In the group receiving typical antipsychotics, mean Y-BOCS scores were 2.40, 2.30, and 2.18 at the beginning, at three weeks and at six weeks after treatment respectively. Also, in the group receiving atypical antipsychotics Y-BOCS scores were 4.12, 4.46, and 4.53 at the beginning, at three weeks and at six weeks after treatment respectively. The difference of Y-BOCS scores in the two groups receiving typical and atypical antipsychotics was close to significance before treatment, and significant at three and six weeks after treatment (p<0.05). In the typical group one patient with positive family history showed a decrease in obsessive-compulsive symptoms, and in the atypical group one patient with positive family history showed an increase in obsessive-compulsive symptoms.

Conclusion: Atypical antipsychotics can induce obsessive-compulsive symptoms in patients with schizophrenia. Despite the importance of family history in the clinical manifestations of obsession in atypical antipsychotic users, the role of this factor in the increase or decrease in obsessive-compulsive symptoms was minimal.