Obsessive-Compulsive Disorder (OCD):

Obsessive-compulsive disorder (OCD) was once thought to be rare, but is now seen as a common, often debilitating condition — involving recurrent, intrusive thoughts (obsessions) prompting neutralizing rituals (compulsions). Compulsive behaviors are repetitive checking, ordering, repeating, and hoarding. Obsessions and compulsions—recognized by those affected as excessive or unreasonable—are time-consuming (more than an hour/day), cause significant distress, and interfere with functioning. Considered an anxiety disorder, OCD is classified separately in  DSM–5 under obsessive-compulsive and related disorders, along with body dysmorphic disorder (BDD). It affects 2-3% of the world population, regardless of cultural background. In children, it’s almost twice as likely to affect boys, but in adults, it reverses to affect more women than men. Also see Exposure Disorders and Personality Disorders