OBSESSIVE-COMPULSIVE disorder (OCD) is a psychiatric condition first described more than 100 years ago.¹ The pathognomonic features of the disorder are persistent, intrusive, senseless thoughts and impulses (obsessions) and repetitive, intentional behaviors (compulsions). Patients with the disorder recognize that their thoughts and behaviors are excessive and unreasonable, and they struggle to resist them. The lifetime prevalence of OCD is estimated to be 1% to 3%, based on population-based surveys conducted in many communities nationally and internationally.^2,3 Although the disorder affects individuals of all ages, the period of greatest risk is from childhood to middle adulthood^4,5 Patients experience a chronic or episodic course with exacerbations that can substantially impair social, occupational, and academic functioning; according to the World Health Organization, OCD is among the 10 most disabling medical conditions worldwide.⁶