Abstract
Around 40–60% of patients with obsessive–compulsive disorder do not show adequate response to selective serotonin reuptake inhibitors (SSRIs). Augmentation strategies are recommended in people who show partial response to SSRI treatment or poor response to multiple SSRIs. In this article, the authors review the evidence for augmentation strategies. The available evidence is predominantly based on small-scale, randomized controlled trials, open-label trials and case series. Antipsychotic augmentation, especially risperidone, haloperidol, aripiprazole and cognitive-behavior therapy have shown the best evidence. Ondansetron, memantine, riluzole, clomipramine, mirtazapine and repetitive transcranial magnetic stimulation over supplementary motor area show some preliminary evidence. Ablative neurosurgery or deep brain stimulation may be tried in carefully selected treatment refractory patients.