Charles Darwin, Martin Luther King Jr., Howard Hughes, and Lady Macbeth all suffered from Obsessive Compulsive Disorder (OCD), which affects approximately 1 in 50 Americans. OCD involves obsessions, which are repetitive unwanted thoughts, and compulsions, which are repetitive behaviors performed to relieve anxiety from the obsessions. Symptoms can range from mildly replaying conversations to severe inability to stop thinking about violence. Diagnosis of OCD requires obsessions and/or compulsions occurring most days for over two weeks, causing distress or interfering with functioning, and not caused by other disorders. Treatment involves therapy and may include medication depending on severity.