DID and MPD are the same thing accoding to the american psychiatry asspciation and the DSM IV TR (Diagnostic Statistical Manual 4th edition Text Revised.) The DSM IV TR is the diagnostic manual used world wide for diagnosing mental disorders along with specific tests geared to diagnose mental disorders such as the MMPI, DES, DDIS, and others.

Basically the label and term Multiple personality Disorder has been changed to the label and term Dissociative Identity Disorder. Just like the label and term Manic Depression is now called the label and term Biporar Disorder.

The psychiarty field changed the name for the disorder called Multiple Personality Disorder to the name Dissociative Identity Disorder because Dissociation is what is actually what the disorder is - the person dissociates (mentally daydreams) thier self out of the abuse situation in which there is no real physical escape of walking or running away from the abuser and when a person daydreams their self out of the abuse situation their memories are stored at the unconscious level of thinking and acted out unconsciously when ever the person daydreams their self out of any triggering situation.