Risperidone as an adjuvant treatment for obsessive-compulsive symptoms in patients with bipolar disorder: a randomized, double-blind, placebo-controlled clinical trial.

Treatment of obsessive-compulsive disorder (OCD) symptoms in patients with bipolar disorder (BD) is challenging. In this research, the therapeutic effects of risperidone on OCD symptoms in patients with BD are investigated. Forty-two patients with concurrent BD and OCD symptoms were randomly assigned to receive risperidone or a placebo in a blinded randomized placebo-controlled trial. The patients of both groups were in the euthymic phase of BD. OCD symptoms were measured by the Yale-Brown Obsessive Compulsive Behavior Scale (YBOCS) before the study initiation and at the 4th,8th, and 12th weeks in each group. All the patients completed the trial with no dropouts. At the initial evaluation, the risperidone and placebo groups did not differ significantly regarding their YBOCS scores. After 12 weeks of treatment, the OCD symptoms were significantly lower in the risperidone group compared to the placebo group [YBOCS: 5(3) vs. 11(6.5), P-value < 0.001]. The number of patients with more than 35% reduction in YBOCS was significantly higher in the risperidone group compared to the placebo group [20/21 (95.23%) vs. 10/21 (47.61%), P-value = 0.001]. Risperidone could effectively reduce OCD symptoms in BD patients. The treatment was safe and well tolerated.