Antipsychotic augmentation strategies in treatment-resistant obsessive-compulsive disorder – a systematic review and meta-analysis

Introduction: Treatment-resistance is a common feature in obsessive-compulsive disorder (OCD). Based on the hypothesis of a dopaminergic hyperactivation in OCD, many studies have examined additive medication with antipsychotics. Methods: A systematic literature search was applied to identify all double-blind, randomized, placebo-controlled trials evaluating the efficacy of a combination therapy with antipsychotics and selective serotonin reuptake inhibitors (SSRIs)/clomipramine in treatment-resistant OCD. Results: Eleven studies investigating quetiapine (N = 4), risperidone (N = 3), olanzapine (N = 2), aripiprazole (N = 1) and haloperidol (N = 1) with a total number of 356 participants were included in the meta-analytic calculations. Significantly more patients responded (defined as a 35% reduction in the Yale–Brown Obsessive Compulsive Scale (Y-BOCS)) to the augmentation with antipsychotics than to placebo (odds ratio (OR) = 3.20; 95% CI: 1.74–5.87). Only for risperidone, but not for quetiapine and olanzapine, a significant efficacy could be identified. The results regarding aripiprazole and haloperidol were inconsistent. Conclusion: Based on the favourable risk-benefit ratio, risperidone can be regarded as the agent of first choice for augmentation treatment with SSRIs/clomipramine in treatment-resistant OCD and should be preferred to quetiapine and olanzapine. Overall, about one third of patients benefit from this therapy option.