Pharmacological treatment of obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a disabling neuropsychiatric disorder. Two treatments have been proven efficacious for the symptoms of OCD: pharmacological treatment with serotonin reuptake inhibitors and cognitive-behavioral therapy (CBT) consisting of exposure and response prevention. This chapter will focus on pharmacological treatments. The only medications which have proved effective for OCD in multisite randomized controlled trials are serotonin reuptake inhibitors, which include clomipramine (a noradrenergic and serotonergic reuptake inhibitor) and the selective serotonin reuptake inhibitors. General guidelines for the use of these medication will be presented, focusing on key issues that arise in clinical practice such as what dose to use, time to response, management of side effects, and duration of treatment. Because many OCD patients will have either a partial response or no response to these medications, evidence-based strategies for managing both partial responders and nonresponders will be described, including the evidence supporting augmentation with other medications or with CBT, and switching to other medications. Finally, novel strategies which are based on an increased understanding of the brain mechanisms underlying OCD and which are under investigation will be reviewed.