Dissociative Identity Disorder (formerly known as MultiplePersonality Disorder)

Dissociative Identity Disorder (formerly known as MultiplePersonality Disorder) is complicated disorder that involves thedevelopment of different personalities through dissociated mentalstates. What does the research state about the origins of thisdisorder? How is this disorder most appropriately treated?(Consider the types of treatment and who is most qualified toprovide this/these type(s) of treatment(s)).