Obsessive-Compulsive Disorder is defined as a disorder characterized by persistent thoughts, impulses or images, which would be known as obsessions. This disorder uses repetitive and stereotyped actions, which are called compulsions, that are carried out in response to the obsessions. An example of this disorder would be a person being obsessed about the thought of leaving the door unlocked or the lights on when you leave the house. Or someone constantly worrying about the germs on other people. This disorder was known as a difficult disorder to treat. There is treatment method to treat OCD which is called exposure and response prevention (ERP). This method of treating OCD involves an extended exposure to the anxiety event while not engaging in the compulsive behavior pattern that can reduce the anxiety which will help the disorder. This disorder is very common in children and adults. Many celebrities and athletes are OCD, which is seen in the video link below.