Obsessive–compulsive disorder
Someone with obsessive–compulsive disorder has unwanted thoughts called obsessions. An obsession is an unwanted thought is happens many times. It is a thought that the person does not want to have. It is normal to have obsessions, but what changes is how people react to the thoughts. People who do not have OCD are able to ignore bad thoughts and move on, or such thoughts do not cause them much distress or anxiety. People who have OCD find it very hard to ignore these thoughts. However, just because someone has unwanted thoughts does not always mean they have OCD. Other brain-based disorders that could result in intrusive thoughts such as Bipolar disorder, Depression, Body dysmorphic disorder, and sometimes Attention-deficit hyperactivity disorder (ADHD).