Obsessive-compulsive disorder: implications of the efficacy of an SSRI, paroxetine.

Obsessive-compulsive disorder (OCD) is an anxiety disorder that commonly presents comorbidly with other psychiatric disorders. The underlying neurobiology of OCD is associated with circuits involving the basal ganglia, thalamus, and the frontal cortex. Randomized, placebo-controlled trials indicate acute and long-term efficacy of potent selective serotonin reuptake inhibitors (SSRIs), such as paroxetine. There is suggestive evidence that higher doses of paroxetine than those used in major depression are needed for benefit in OCD. Because of their safety and beneficial adverse-event profile, the SSRIs have become the leading choice in the pharmacological management of OCD.