Obsessive Compulsive Disorder (OCD) is an anxiety disorder characterized by recurrent obsessions and/or compulsions. Obsessions are persistent thoughts, images or impulses which are experienced by the sufferer as intrusive or inappropriate. Compulsions are repetitive behaviours or mental acts that the person feels driven to perform, and are intended to reduce distress.
There are three common forms of OCD:
OCD, especially where someone's rituals are highly repetitive and are disturbing the person's life might also be accompanied about fears of going mad since the sufferer knows that magical thinking is odd.