Antipsychotic augmentation in the treatment of obsessive-compulsive disorder

Most studies suggest that obsessive-compulsive disorder runs a chronic course. Only 40%–70% of patients respond to first-line treatment with selective serotonin reuptake inhibitors (SSRIs). The most common pharmacological strategy used in clinical practice for partial responders to SSRIs is augmentation with an atypical antipsychotic. This article aims to review the efficacy, tolerability, and comparative efficacy of antipsychotics as augmenting agents in patients who showed inadequate response to SSRIs. In addition to case reports and case series, 15 randomized controls trials, 6 meta-analyses, and 3 expert guidelines have been examined. The findings suggest that one in three SSRI nonresponders improve with antipsychotic augmentation. The presence of comorbid tics and/or schizotypal disorder may predict a better response to antipsychotic augmentation. Among antipsychotics, risperidone, and aripiprazole have the best evidence, with haloperidol being considered second in-line owing to its unfavorable side effect profile. Guidelines recommend that antipsychotics be administered at a low-to-medium dosage for a duration not exceeding 3 months, with mandatory discontinuation if there is no response. Larger studies and head-to-head trials are needed to further explore this treatment strategy.