Georgia football legend Herschel Walker's book "Breaking Free" debuted this week and is shining new light on dissociative identity disorder, an ages-old subject in movies.

Having multiple personalities may not be as simple as "Psycho" (you know, Norman Bates being himself and, in his mind, his aggressive mother), but Hollywood has used the disorder not only for horror, but for comedy, fantasy and for depicting real life.

A few examples:

"X-Men: The Last Stand" (2006) —- Famke Janssen's character can be either the telepathic Jean Grey or the overly aggressive, cosmic Phoenix.

"Me, Myself & Irene" (2000) —- The pliable Jim Carrey is either mild-mannered Charlie or wild-mannered Hank in the Farrelly brothers' bawdy comedy.

"The Nutty Professor" (1996) —- When Eddie Murphy's overweight professor takes a certain chemical, he becomes the tres slim and tres obnoxious Buddy Love.

"The Three Faces of Eve" (1957) —- Georgia-born Joanne Woodward won an Oscar portraying Eve White, who developed two other personalities. The movie is loosely based on the true story of Chris Costner-Sizemore.

"Dr. Jekyll and Mr. Hyde" (1931) —- Fredric March won his first of two Oscars playing the classic dissociative identity disorder sufferer, his problems tied to a potion, from Robert Louis Stevenson's novel.

"The Lord of the Rings: The Two Towers" (2002) —- A double-personality oddity, the remarkable, humanesque Gollum performs a head-spinning soliloquy that's a riveting argument between his good and evil sides.