Obsessive–compulsive disorder
Behavioral therapy and cognitive behavioral therapy are used to help people with obsessive–compulsive disorder. The therapy works by making people be in places where they have their obsessive thoughts. They are then made to not do their compulsion. Over time, the person becomes used to the place or things that causes them to have their obsessive thoughts. An example of this is someone who is afraid of dirt having dirt put on their hands without being able to wash it off.