The "alters" are said to occur spontaneously and involuntarily, and function more or less independently of each other. The unity of consciousness, by which we identify our selves, is said to be absent in MPD. Another symptom of MPD is significant amnesia, which can't be explained by ordinary forgetfulness. In 1994, the American Psychiatric Association's DMS-IV replaced the designation of MPD with DID: dissociative identity disorder (DSM-IV 4th ed.). The label may have changed, but the list of symptoms remained essentially the same.
In order to be dx'd (diagnosed) DID one must have the presence of two or more distinct identities or personality states (each with its own relatively enduring pattern of perceiving, relating to, and thinking about the environment and self). At least two of these identities or personality states recurrently take control of the person's behavior. An inability to recall important personal information that is too extensive to be explained by ordinary forgetfulness. Finally, the disturbance is not due to the direct physiological effects of a substance (e.g., blackouts or chaotic behavior during Alcohol Intoxication) or a general medical condition (DSM-IV 4th ed.). .
When faced with overwhelmingly traumatic situations from which there is no physical escape, a child may resort to "going away" in her or his head. This ability is typically used by children as an extremely effective defense against acute physical and emotional pain, or anxious anticipation of that pain. By this dissociative process, thoughts, feelings, memories, and perceptions of the traumatic experiences can be separated off psychologically, allowing the child to function as if the trauma had not occurred. Individuals most likely to develop (DID) MPD present several factors in a common profile. They have endured repetitive, overwhelming, and often life-threatening trauma at a sensitive developmental stage of childhood (usually before the age of nine), and they may possess a biological predisposition for a high level of hypnotizablitiy (Kluft, 1982).
