The Efficacy of Aripiprazole versus Risperidone as Augmentation Therapy in the Treatment of the Resistant Obsessive-Compulsive Disorder: A Double-Blind Clinical Trial

Background: Obsessive-compulsive disorder (OCD) is the fourth common psychiatric disorder. Among the anxiety disorders, OCD has the least therapeutic response and 40-60 of OCD patients do not satisfactorily respond to the first-line standard treatment known as treatment-resistant OCD. One of the best therapeutic strategies is the augmentation therapy, which is adding antipsychotics to the standard treatment (SSRIs). Objectives: In this study, the efficacy of risperidone and aripiprazole was compared as an augmentation therapy. Methods: In this double blind randomized clinical trial, 100 patients with treatment-resistant OCD were diagnosed based on the DSM-IV-TR and were followed for twelve weeks. The patients were randomly divided into two groups of aripiprazole and risperidone and received an average daily dose of 5 mg and 1.5 mg for twelve weeks, respectively. The efficacy of treatment was measured and compared by the Yale-brown obsessive compulsive scale (Y-BOCS) at 4, 8 and 12 weeks. Results: The mean Y-BOCS score of patients in risperidone and aripiprazole groups were 25.26 ± 4.17 and 25.02 ± 4.46; respectively and had no significant difference (P = 0.79) at the beginning of the trial. At the end of the study (12th week) it was changed for the risperidone and aripiprazole groups to 20.00 ± 4.45 and 16.24 ± 4.41, respectively (P < 0.001). Furthermore, there was a significant decreasing trend of Y-BOCS scores in both groups, which was demonstrated by the repeated measurement analysis (P < 00.1). Conclusions: It was found that both aripiprazole and risperidone could be effective in treatment of treatment-resistant OCD patients. However, aripiprazole showed a higher efficacy compared to risperidone. © 2016, Author(s).