Treating OCD: what to do when first-line therapies fail

Objective: To provide a clinically-focused review of the biological treatment of treatment-resistant obsessive compulsive disorder (OCD). Conclusions: There is a paucity of research on how to manage OCD patients who fail to respond adequately to first line therapies. High-dose selective serotonin reuptake inhibitors (SSRIs) and clomipramine have good evidence-based data. Combinations of SSRIs have little support in clinical trials, but the combination of SSRIs and clomipramine can be helpful: careful clinical and cardiac monitoring is required. Certain adjunctive antipsychotics have a reasonable evidence base in OCD, but their use also needs to be weighed against the potential side effect burden. In patients with substantial generalised anxiety symptoms, clonazepam is worth considering. Of the other augmenting strategies, memantine and ondansetron appear useful in some cases, and are well tolerated. Topiramate might ameliorate compulsions to some degree, but it is less well tolerated. If all these strategies, along with expert psychological therapy, fail, careful consideration should be given to deep brain stimulation (DBS), which has an emerging evidence base and which can result in dramatic benefits for some individuals. For some patients, gamma radiosurgery might also still have a place.