Multiple Personality Disorder aka Dissociative Identity Disorder

Urmila Matondkar was diagnosed with MPD in Bhoot though the truth was something else. :)
Multiple Personality Disorder or MPD now has a new name as of 2000. It is now called DID or Dissociative Identity Disorder. One of the reasons was that the original term was being thrown into disrepute by many people giving phony demonstrations of alter switching during television talk shows.
As the former name implies, MPD/DID is a mental condition in which 2 or more personalities appear to inhabit a single body. "Dissociation is an act of disconnecting, locking the memory or pain in a 'suitcase' and storing the 'suitcase' in the back of the brain. Dissociation Identity Disorder is the phenomena of completely disconnecting oneself from a memory (or memories) and the emotions around the memory(ies), creating a separate identity to hold memories and emotions." (Arthur Zeilstra and Janet Howden).
Multiple Personality Disorder or Dissociative Identity Disorder is characterized by the following symptoms according to the handbook that Psychiatrists and Psychologists use called the DSM-IV-TR:
The presence of two or more distinct identities or personality states (each with is 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.
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 medial condition (e.g., complex partial seizures). This would not include imaginary playmates or other fantasy play.
In layman’s terms this means that in order to have Multiple Personality Disorder or DID, to use the newer title, a person will have to exhibit several separate personalities and often lose time because the person’s main personality or ego state would not be fully conscious while one of the other personalities is dominant.
A person suffering from MPD or Dissociative Identity Disorder may have only two separate personalities or 10. They might be partially aware of the other personalities or not. Often the other personalities or what is called alters have separate names and/or separate genders.
The origin or cause of MDP or Dissociative Identity Disorder is most commonly due to massive physical, sexual, and/or emotional abuse when a person is very young. The abuse is so overwhelming for the individual that in order to mentally and emotionally block out the pain a person will dissociate to such an extent that they will develop a separate ego state to experience it while what we think of as the real person blocks out memory. A minority of mental health professionals accepted MPD/DID as a real phenomenon during the 1980s and early 1990s. Few continue this belief today. Most professional therapists believe that it is an iatrogenic (physician induced) disorder that either does not appear naturally, or is almost non-existent. However, belief in MPD/DID is still commonly found among conservative Christian counselors. Dissociation itself is a common experience. Most people have observed mild dissociative episodes in which they lose touch with their surroundings. Examples include daydreaming, highway hypnosis, or losing oneself in a movie or book. MPD is viewed by some as an extreme level of dissociation, "which may result in serious impairment or inability to function”.
The goal of treatment is to get the person suffering from MPD or Dissociative Identity Disorder to re-experience all their split off parts and to accept them as part of the person. Then it is important to relive the trauma and integrate it into their lives devoid of the original pain.