On the other hand, some films that purport to recount authentic psychiatric cases have raised doubts. Thus, psychiatrist Herbert Spiegel, who consulted in the "Sybil" case, has stated the view that Shirley Ardell Mason ("Sybil") had been manipulated by her Freudian psychiatrist, Dr. Cornelia B. Wilbur, into acting like a person with dissociative identity disorder ("mulitiple personality disorder").
Among the least convincing "serious" films, especially at several decades' remove from their production, are those that attempt to be didactic, such as Spellbound and The Snake Pit.
In action, thriller and horror movies, characters who suffer from mental illnesses often resort to violence or dangerous behavior. Examples are Leatherface, Renfield, Hannibal Lecter, Colonel Kurtz, John Rambo.
Mental illness is often used for comedic effect in films. "Crazy" characters provide amusing moments in film comedies and cartoons, often depicting "mental illness" as a type of fun for the characters who, due to their illness, have an alibi to act stupid, weird or annoying to their environment. Examples of this type of "mentally ill" comedic characters include Daffy Duck, Woody Woodpecker, The Marx Brothers, Ace Ventura, The Mask, several characters in the Monty Python films.
See also: Fictional characters with mental illness