Multiple Personality Disorder/Disassociative Identity Disorder:
Multiple Personality Disorder (MPD), or Dual Personalities has been around for ages, but not really recognized as a disease until fairly recently medically. Dual Personalites was coined as Multiple Personality Disorder in the 1970's. However, there was medical debate over whether or not this was a correct term for the disease, and it was changed to Disassociative Identity Disorder (DID).

The basic feature of Dissociative Identity Disorder is the presence of two or more distinct identities or personalities that take control of behaviour. (In Alfred's case, his personality of himself would control his actions part of the time, while his Alexia personality would be in control other times). There is an inability to recall important personal information, the extent of which is too great to be explained by ordinary forgetfulness. This disassociation is not directly linked to other generic medical problems or direct effects of a substance.

DID reflects a failure to integrate various aspects of identity, memory, and consciousness. Each personality state may be experienced as if it has a distinct personal history, self-image, and identity, including a separate name. Usually there is a primary identity that carries the individual's given name and is passive, dependent, guilty, and depressed. The alternate identities frequently have different names and characteristics that contrast with the primary identity (e.g., are hostile, controlling, and self-destructive). Particular identities may emerge in specific circumstances and may differ in reported age and gender, vocabulary, general knowledge, or predominant affect. Alternate identities are experienced as taking control in sequence, one at the expense of the other, and may deny knowledge of one another, be critical of one another, or appear to be in open conflict. Occasionally, one or more powerful identities allocate time to the others. Aggressive or hostile identities may at times interrupt activities or place the others in uncomfortable situations.

Individuals with this disorder experience frequent gaps in memory for personal history, both remote and recent. The amnesia is frequently asymmetrical. The more passive identities tend to have more constricted memories, whereas the more hostile, controlling, or "protector" identities have more complete memories. An identity that is not in control may nonetheless gain access to consciousness by producing auditory or visual hallucinations (e.g., a voice giving instructions). Evidence of amnesia may be uncovered by reports from others who have witnessed behavior that is disavowed by the individual or by the individual's own discoveries (e.g., finding items of clothing at home that the individual cannot remember having bought). There may be loss of memory not only for recurrent periods of time, but also an overall loss of biographical memory for some extended period of childhood. Transitions among identities are often triggered by psychosocial stress. The time required to switch from one identity to another is usually a matter of seconds, but, less frequently, may be gradual. The number of identities reported ranges from 2 to more than 100. Half of reported cases include individuals with 10 or fewer identities.

- Taken from Disassociation.com

Revert