• obsessive–compulsive disorder;
  • behavioral therapy;
  • exposure and response/ritual prevention;
  • cognitive behavioral therapy;
  • serotonin-reuptake inhibitors;
  • pharmacotherapy;
  • meta-analysis;
  • systematic review


Effective treatments for obsessive–compulsive disorder (OCD) include behavioral therapy (exposure and response/ritual prevention and cognitive behavioral therapy) and serotonin-reuptake inhibitors (SRIs); however, the relative efficacy of these treatments is not well established. We sought to review evidence from head-to-head randomized-controlled trials (RCTs) of behavioral therapy and SRIs in the treatment of OCD.


A systematic search of multiple databases was conducted from first available date to June 30, 2012, for RCTs in the treatment of OCD among outpatients, comparing behavioral therapy and SRIs, alone or combined. Two independent reviewers evaluated studies for eligibility and risk of bias. The main outcome measure was posttreatment mean Yale-Brown Obsessive–Compulsive Scale (YBOCS) score.


We identified 2,186 unique articles. Fifteen articles were included, describing 13 RCTs. Pooled standardized mean difference (SMD; 95% confidence intervals) in YBOCS score significantly favored behavioral therapy over SRIs (0.37; 0.10, 0.64; P = .007), but not in a subset of trials that used selective SRIs (0.22; −0.02, 0.47; P = .070). Within individual trials, effect sizes significantly favored the combination of behavioral therapy plus an SRI over an SRI, but not behavioral therapy, alone.


This review provides evidence that, among outpatients with OCD, behavioral therapy is more effective than SRIs, overall, but not selective SRIs. Furthermore, the combination of behavioral therapy plus an SRI is more effective than an SRI alone. These data may be used to inform the development of evidence-based treatment guidelines; however, more studies are also needed to further evaluate the relative efficacy of these interventions.