 Background and Purpose: Obsessive compulsive disorder affects approximately 3 of the population. Treatment options include the selective serotonin reuptake inhibitors SSRIs, dual serotonin and norepinephrine reuptake inhibitors, and behavioral therapy. A recent double-blind, placebo-controlled trial demonstrated that citalopram is effective in the treatment of OCD. Escitalopram is a new SSRI that may be more effective than other SSRIs for the treatment of major depression and may have fewer side effects. This study aims to assess the efficacy of escitalopram for the treatment of OCD. 