Dissociative identity disorder is the latest clinical name for what used to be known as multiple personality disorder (MPD). The case that first launched MPD into the public's general awareness is that of Sybil Dorsett, a pseudonym for Shirley Ardell Mason, who was treated for years by Dr. Cornelia Wilbur, one of the pioneer psychiatrists in the field.
There is a lot of controversy within the psychiatric community whether the disorder is even real or not. Some professionals believe that MPD is an iatrogenic illness, i.e., caused by the psychotherapist. Most patients who are diagnosed with the illness are highly suggestible and are able to enter into a hypnotic state very easily.
The American Psychiatric Association defined MPD as a distinct mental illness in the late 1970's. According to the DSM-IV, a diagnosis of dissociative identity disorder (DID) requires the following:
- The presence of two or more distinct identities or personality states, each with its own relatively enduring pattern of perceiving, relating to, and thinking about the environment and self.
- At least two of these identities or personality states recurrently take control of the person's behavior.
- Inability to recall important personal information that is too extensive to be explained by ordinary forgetfulness.
- The disturbance is not due to the direct physiological effects of a substance (e.g., blackouts or chaotic behavior during alcohol intoxication) or a general medical condition (e.g., complex partial seizures). In children, the symptoms are not attributable to imaginary playmates or other fantasy play. A patient history, x-rays, blood tests, and other procedures can be used to eliminate symptoms being due to traumatic brain injury, medication, sleep deprivation, or intoxicants, all of which can mimic symptoms of DID.
I think it's important to realize that dissociation and/or depersonalization also occur within patients suffering from posttraumatic stress disorder (PTSD). I also think that any child or adult who is initially diagnosed with DID should be evaluated by a second clinician before upholding the diagnosis. This condition shares so many symptoms with other illnesses that I really believe a second opinion is necessary. Just my two cents...