In a previous meta-analysis investigating pharmacological treatment options in obsessive-compulsive disorder (OCD) we determined a significant efficacy for the augmentation of serotonin reuptake inhibitors (SRIs) with antipsychotic drugs. Because new relevant double-blind, randomized, placebo-controlled trials (DB-RCTs) evaluating new antipsychotics were conducted, we updated our meta-analysis.

We included all DB-RCTs that compared augmentation of SRIs with antipsychotics to placebo augmentation in SRI-resistant OCD. Meta-analytic outcomes were treatment response defined by 35% reduction in Yale–Brown Obsessive–Compulsive Scale (Y-BOCS) total score and mean changes in Y-BOCS total score. Effect sizes were standardized mean differences (SMD) and risk ratios (RR).

Fourteen DB-RCTs (n=467) investigating quetiapine (N=5, n=178), risperidone (N=3, n=72), aripiprazole (N=2, n=79),olanzapine (N=2, n=70), haloperidol (N=1, n=34), and paliperidone (N=1, n=34) were incorporated. The pooled antipsychotic augmentation group was significantly superior to the placebo group in terms of response rates (N=14,n=467; RR=1.98, 95% CI: 1.23 to 3.19;p=0.005) and mean change in Y-BOCS total score (N=14, n=465, SMD=-0.6, 95% CI: -0.97 to -0.23; p=0.002). Concerning the individual antipsychotics, aripiprazole and risperidone significantly outperformed placebo in terms of both responder rates and mean Y-BOCS change. Olanzapine, paliperidone, and quetiapine were not significantly different from the control group. There was no significant heterogeneity and no evidence for publication bias.

Aripiprazole and risperidone augmentation of SRIs canbe regarded as evidence-based treatment options in treatment-resistant OCD and showed superiority over olanzapine, paliperidone, and quetiapine. About one third of all SRI-resistant OCD subjects responded to augmentation with antipsychotic drugs.