What is Multiple Personality Syndrome?

Answer 1

a psychiatric diagnosis that describes a mental illness in which a single person dissasociates from themself and displays multiple distinct identities or personalities, each with its own pattern of perceiving and interacting with the environment. it is also referred to as multiple personality disorder - MPD or dissasociative identity disorder, DID. It is not to be confused with natural or 'healthy' multiplicity, which is when several people/conciousnesses share one body. The definining difference is self-awareness, although most multiple groups will also not meet other standard MPD/DID criteria such as 'depersonalization of self' and often share memories and thoughts.

Answer 2

I think you mean Multiple Personality Disorder (MPD) which is now called Dissociative Identity Disorder (DID). When someone has experienced ongoing severe trauma usually in their childhood, they disconnect from the traumatic experience (they distance themselves from awareness of what is occurring). They go into a states of mind where they start to think that the abuse is not happening them, but to someone else (a survival mechanism for a child who endures abuse and it may be their only escape).

The person may begin to split of alternate identities (referred to as 'alters'). These alters can be different from the 'host' (the main person - the one that controls the body), though not all of the alters can be different from the host. They can have their own personal history - separate name, age, gender, self image. The job of the alters is to protect the host from the memories of the trauma. There can be as little as 1 alter to as many as 100.