Multiple personality disorder or split personality disorder is a very controversial diagnosis among Doctors. Some dont think it exists, other wouldn't diagnose it, because it could be written of as psychosis or many other conditions, but many believe its confided to the Americas - a type of social disease.
These days its classified as 'Dissociative identity disorder' and although the cause hasn't been pin-pointed, experience has show that uncopeable stress, prolonged childhood abuse and other traumatic incidents are often a factor.

I looked into some medical journals and couldn't find much research being done on it either...i guess its not a big priority among researchers? Acolon_5, Do u know anything of studies being done, or current treatments?

Studies, no, not really. The name was changed a few years ago to Dissociative Identity Disorder (DID) to avoid confusion with personality disorders which is another can of worms altogether. It is gaining more acceptance among health professionals in the past few years. In our area alone we were able to find 4 therapists who specialized in Dissociative Disorders and Trauma.

Since it is not a chemical imbalance drugs do very little to treat the disorder. Many who have this disorder are treated as Bi-Polar or some type of Schizo and receive medication that is ineffective (due to a misdiagnosis). The old treatment involved reliving though the patients trauma. Due to the nature of this disorder, full sense flashbacks are very common, and the patients would basically live through the abuse and trauma again. This was a long, extremely painful, and quite often dangerous treatment.

Most often now, psychotherapy (talk therapy) is the most common treatment used. Working towards becoming functional is usually the first step. Having the parts of the mind work together or integration, if so desired is usually the goal to work towards.

Fully breakthough dose. The report can be found here!