Hi doctors, was just wondering what is multiple personality disorder and are there different forms of it?

A spectrum: Dissociation is a spectrum. It can vary from normal highway hypnosis where you've driven for a while and then suddenly come to and you can't remember having driven the past several miles, all the way to having full-blown multiple personality disorder which is referred to as dissociative identity disorder. In between is a large spectrum of conditions based on amnesia, repressed memories, feelings, sensations, smells, visualizations, tastes, and virtually any part of a traumatic experience that a person can push into the back recesses of their mind. Mild forms include what are called ego state disorders. More complex cases are called dissociative disorder not otherwise specified. There are also conditions such as depersonalization disorder which although being a form of dissociation does not have its roots in trauma. In extreme dissociation a person creates an alter ego or self that takes on the experiences that the person experienced as they were going through a significant trauma. This is called a split off part of the self. Because the trauma progresses, this split off part will likely split off another part that is identified with the aggressor. These parts tend to be disoriented to person place and time. They have separate wills identities and roles.

Multiple personality: MPD, now called dissociative identity disorder is characterized by two or more distinct identity states known as alters in addition to the patient him/her self. These identity states will seem fragmentary and partially unaware of the others, each with varying degrees of disturbance, The alters tend to be more active and aggressive, while the patient's core personality will be more passive.