This document discusses multiple personality disorder (MPD), now called dissociative identity disorder (DID). It describes some key aspects of the disorder, including that individuals may have two or more distinct personalities that control their behavior. There is controversy around MPD as it is not scientifically proven. Treatment aims to help individuals learn to control their symptoms and integrate their personalities. The document provides examples of individuals who claim to have MPD and how media portrayals have shaped views of the disorder.