“As an undergraduate student in psychology, I was taught that multiple personalities were a very rare and bizarre disorder. That is all that I was taught on ... It soon became apparent that what I had been taught was simply not true. Not only was I meeting people with multiplicity; these individuals entering my life were normal human beings with much to offer. They were simply people who had endured more than their share of pain in this life and were struggling to make sense of it.”
― Deborah Bray Haddock, The Dissociative Identity Disorder Sourcebook
Individuals with dissociative identity disorder (DID) are in therapy for an average of ten years before they are diagnosed and spend an additional average of ten years in therapy for their DID. Patients with DID may benefit from some combination of: talk and behavioral therapies including cognitive behavioral therapy and dialectic behavior therapy; art, music, and play therapy; eye movement desensitization and reprocessing; family therapy; medication. Hypnotherapy is inappropriate for patients with DID because hypnosis risks strengthening the dissociative barriers between alters, changing or falsifying memories, flooding the patient with flashbacks, and invalidating the individual’s testimony in court. Details about specific treatments for DID can be found here.
Some individuals with DID choose to integrate, or assimilate all of their alters into one personality, but others choose cooperation and communication instead. Many find the idea of integration difficult to swallow, find integration unnecessary after posttraumatic stress disorder (PTSD) symptoms have been treated and co-consciousness has been achieved, or find it impossible to integrate all of their parts or cannot maintain one integrated personality over time or when faced with stress. Some question if integration is even permanently possible, and many therapists are less insistent on integration as the only possible treatment for DID as many were in the past. However, even individuals with DID who are vocal about their desire not to integrate are likely to spontaneously integrate some alters and fragments as they process and heal, some individuals who are integrated are convinced that integration is the best option, and some studies (such as this one) do suggest that integration is the option most likely to result in long-term stability and healing.
Full integration requires accepting one's alters, accepting and processing one's trauma history, and owning all thoughts, feelings, memories, urges, skills, etc that were previously assigned to various parts of the self. Integration is complete when there are no subjective differences between the parts involved. For deliberate integration of more developed alters, the remaining identity is not meant to be any of the parts involved in the integration but a more well rounded and stable part or individual who to some degree contains and owns all of the conflicting aspects that the parts involved contained before merging. However, when integration involves one alter who is significantly more well developed than the other alters or fragments involved, the result may be that the more developed alters feels only that they have gained some of the skills, traits, preferences, or views of the other parts involved, if that.
Here is an article by an individual with DID who wants to integrate. It details the difference between wanting alters to disappear (which is impossible) and accepting them fully (which is necessary for integration).
Here is an article by an individual who had DID and chose to integrate. It details what integration is and why the author views it as the best goal for healing.
Here is a blog post from a therapist who specializes in trauma and dissociation and who believes that integration is neither necessary nor always helpful.