The 1976 TV movie Sybil was based on a book of the same name written by Flora Rheta Schreiber. Both of these accounts were based on a real-life patient and psychiatrist but recently there has been controversy over whether the real Sybil actually had multiple personalities at all. Other movies like The Three Faces of Eve, Psycho, and Me, Myself & Irene have also dealt with multiple personality. Once this disorder was popularized in the movies, the number of diagnosed cases increased dramatically.

Multiple personality disorder is no longer the term used to refer to this disease. It is now referred to as Dissociative Identity Disorder (DID). DID is defined as a disorder where two or more distinct personality states or identities alternately control or take over a person’s mind. This disorder is a result of many factors, most commonly severe emotional stress.