Brain stimulation techniques in the treatment of obsessive-compulsive disorder : current and future directions

Recent studies on the epidemiology of obsessive-compulsive disorder (OCD) estimate 50 million patients suffer from OCD worldwide, thus making it a global problem. The treatment of OCD has changed substantially over the last 2 decades following the introduction of selective serotonin reuptake inhibitors, which provide symptom improvement in approximately 60% of patients. However, some patients remain resistant to the standard pharmacologic and behavioral treatments. Although some treatment-resistant patients respond to pharmacologic augmentations, others do not, and there is evidence that some of the most severe cases benefit from treatment with neurosurgical interventions. Besides pharmacologic, behavioral, and neurosurgical approaches, different brain stimulation methods-transcranial magnetic stimulation, deep brain stimulation, and electroconvulsive therapy-have been investigated in treatment-resistant patients with OCD. However, available data about the use of these techniques in OCD treatment are quite limited in terms of sample size and study design, given the difficulty in conducting standard blinded trials for these procedures. In addition, none of the mentioned treatments have received Food and Drug Administration approval for the treatment of OCD. Nevertheless, promising findings regarding efficacy, tolerability, and non-invasiveness and/or reversibility of these techniques have increased interest in investigating their use in treatment-resistant OCD.