In theory, multiple personality disorder is caused by psychological and neurological changes that cause a person to dissociate, or become detached from, his normal sense of who he is. Some theories on multiple personality disorder suggest the problem is caused by chemical or neurological changes. Others suggest multiple personality disorder is the brain's attempt to cope with extreme trauma, as in the case of severe abuse, typically in early childhood and that the dissociation is a form of self-hypnosis. Repressed memories are also believed by some to be a part of multiple personality disorder.
Multiple personality disorder became sensationalized in the media in the seventies by movies like Sybil and The Three Faces of Eve, books such as Prism: Andrea's World, and news accounts such as that of Billy Milligan, who used multiple personality disorder as his defense in trial involving robbery and rape charges.
Research on multiple personality disorder is intriguing, but some say it is fraught with fuzzy, inexact data. Billy Milligan, for example, was said to have personalities with different IQs and eyeglass prescriptions. Thought provoking, but difficult to verify.
Multiple personality disorder, like many psychiatric disorders, can range from mild to debilitating. In many cases, sufferers of multiple personality disorder do not seek treatment until their lives have become unmanageable, or they have legal problems. Multiple personality disorder is typically treated with a combination of therapy and psychotropic medication.