OCD is associated with many other distinct forms of mental illness. They are like OCD in some ways and different in others. For example, individuals with body dysmorphic disorder (DBB) believe that there is something terribly wrong with their bodies or their appearance. They obsess over minor flaws in the mirror and come to believe that these imperfections make them horribly deformed. Such idiosyncrasies may be bumps on the nose, a weak jaw, a thin mouth, wrinkles, mild acne, and so on.
Of course, these small imperfections are rarely, if ever, noticed by others. These obsessions are alleviated by compulsive dermatology visits, cosmetic surgery, checking themselves in the mirror, agoraphobia due to embarrassment, frequent requests from assurance from others, and so on. In these respects, BDD is similar to OCD. However, some of the symptoms, such as wearing a wig or getting plastic surgery, do not involve repetitive rituals.
Next, there is hypochondriasis. Such individuals have intense fears that they have a major illness. This results from pathological misinterpretations of bodily sensations. Even multiple trips to the doctor’s office will not alleviate their anxiety. This is similar to OCD because of the obsessive concern for one’s body and the repetitive requests for reassurance from others.
Trichotillomania involves pulling one’s hair out compulsively. This may result in muscle strains, skin infections and social isolation. They may feel compelled to wear wigs after they have pulled noticeable amounts of their hair out. Pulling hair out may result in pleasure whereas others simply experience an overwhelming urg to do so, and insist that this tension is only relieved when they are allowed to do so. The choice of which hairs to pull sometimes involves being a specific color or residing in a certain location. The pulled hair is then sometimes preserved in a ritualistic manner, eaten, or brushed against the face. Unlike OCD, trichotillomania is not associated with as much anxiety and its symptoms are worse at night. Pulling the hair may also be associated with pleasure, whereas OCD compulsions merely alleviate anxiety produced by obsessions.
Tic disorders also bear some similarity to OCD. They are urges towards repetitive movements or vocalizations which the individual can repress only for a short time.They get worse when under stress and are not as severe when the individual is absorbed in something. They may involve sniffing, stamping, facial grimacing, blinking, barking, grunting, repeating words, throat-clearing and so on. Tourette syndrome is diagnosed when a person engages in several motor tics along with a vocal tic. Unlike OCD, however, tics are not designed to reduce anxiety, are not correlated with obsessional thoughts or worries, are more often associated with socially inappropriate behaviors and are associated with boredom and either unusually low or unusually high arousal.
Finally, those with eating disorders have an obsessive concern with their appearance. About 20 to 30 percent of those with an eating disorder have OCD. They are particularly concerned with their weight and, like those with BDD, have a distorted view of their body. They may abuse laxatives to lose weight, exercise excessively, have restricted diets or induce vomiting to get rid of calories.