Dissociative Identity Disorder

Dissociative Identity Disorder (formerly known as multiple personality disorder): Characterized by the presence of two or more distinct identities or personality states that recurrently take control of the individual's behavior accompanied by an inability to recall important personal information that is too extensive to be explained by ordinary forgetfulness (DSM-IV p. 477). Eating disorders may appear among the manifestations of DID while dissociative states (depersonalization, trance-like states, out-of-body experiences, amnesias, and multiple personalities) have been seen in cases of eating disorders. Source 1, 2

D.I.D. reflects a failure to integrate various aspects of identity, memory and consciousness. Each personality state may be experienced as if it is a distinct individual, with a unique history, image, identity, name, etc. There is typically a primary identity and then various alternate identities emerge under specific circumstances often with individual names, ages, genders, knowledge base, etc.
The individual may experience disruptions in consciousness, memory, sense of identity, perception and experience feelings of emotional separation as well as manifest post-traumatic symptoms (nightmares, flashbacks, and startled responses), self-mutilation and/or suicidal and aggressive behaviors. It is diagnosed 3-9 times more often in adult females than in adult males and females tend to have more identities than males (females average 15 or more compared to males averaging 8 identities). DID tends to be chronic and recurrent with average time period from onset to diagnosis being 6-7 years.  Source: DSM-IV-TR