Disassociative Identity Disorder
THE DISSOCIATIVE DISORDERS
The Diagnostic and Statistical Manual (DSM III-R) lists 4 Dissociative Disorders: (1) psychogenic amnesia; (2) psychogenic fugue; (3) depersonalization disorder: and (4) multiple personality. In addition, there is a catch-all category covering atypical dissociative presentations.
Psychogenic Amnesia is a sudden inability to recall important personal information that is too extensive to be explained by ordinary forgetfulness and is not associated with an organic mental disorder. The completeness of the amnesia and the time period involved may vary widely.
Psychogenic fugue involves sudden, unexpected travel away a person's usual environment, with an inability to recall the past, that occurs in the absence of an organic mental disorder. There is often the assumption of a new identity.
Depersonalization feelings may occur as a symptom in a wide range of psychiatric and neurological conditions. Depersonalization is only considered to be a diagnosable disorder when it occurs in the absence of one of these other conditions, and is severe enough to cause social or occupational impairment or marked distress.
Depersonalization involves an alteration in the individual's sense of self. The person feels unreal, as if in a dream, like a machine, dead, self-estranged, or otherwise significantly changed from normal. Sensory disturbances such as anesthesias, paresthesias, a change in the sense of body size or body parts, macroscopia or microscopia, or the experience of being outside of one's body and watching one's self from a distance or looking down from above are often present. The individual may also have passive-influence experiences, feeling controlled or as if functions such as speech are not under the individual's control but have a "mind of their own."
DISSOCIATIVE DISORDER NOT OTHERWISE SPECIFIED (DDNOS)
Dissociative Disorder Not Otherwise Specified (DDNOS) is a residual category to accommodate phenomena that do not fit into the conventional DSM-III/DSM-III-R dissociative disorders. There must still be found to be present a dissociative alteration in the normally unified functions of identity, memory, or consciousness.
MULTIPLE PERSONALITY DISORDER (MPD)
Multiple Personality Disorder (MPD) is the "ultimate" Dissociative Disorder. MPD is a complex and chronic condition in which all of the elements of the other dissociative disorders may be found. Individuals with MPD will, at times, manifest psychogenic amnesia, fugue episodes, and profound depersonalization.
For a diagnosis of MPD there must be present two or more distinct personalities. Each must have a relatively enduring pattern of perceiving, relating to, and thinking about the environment and self. At least 2 personalities must recurrently take full control of the person's behavior. In the diagnostic process, a continuum is often used ranging from "fragment" (an ego state with a consistent sense of self and pattern of behavior) to "personality" (with a much more full range of function, emotion, and history). For MPD there should be at least 2 more fully structured and developed personalities.
FREQUENCY OF MPD
There is little reliable epidemiological data on any of the dissociative disorders. The mental health system does not routinely screen for MPD and there is a lingering perception that it is a rare disorder. There are, however, strong indications that the number of patients with MPD is in the thousands. Assessment studies of large groups of MPD patients (in the hundreds) reveal a common pattern of past treatment. The MPD patient will be likely to have received many psychiatric misdiagnoses, will have experienced many ineffective psychiatric hospital admissions, and will have developed a distrust of the mental health system.
The phenomenology of MPD works against early diagnosis. On a given hospital admission an MPD patient may fully meet DSM criteria for 5 or 6 vastly different diagnoses, depending on which personalities are in executive control or exerting influence at different times during the admission. Also, some forms of MPD crises (rapid switching between personalities, continual flashbacks, intense disorientation, misidentification of staff as abusers) can resemble psychotic states.
Limited studies have indicated that as much as 5% of psychiatric inpatients will be undiagnosed MPD or Dissociative Disorder patients.
MPD is generally recognized as being a psychobiological response to overwhelming trauma during childhood. Effective treatment of MPD requires an understanding of the impact of that trauma and the adaptive role that dissociation played. The predominant theory is that repeated childhood trauma enhances normal dissociative capacities, which in turn provide the basis for the creation and elaboration of alter personality states over time.
The primary treatment of MPD is insight-oriented psychotherapy, with therapeutic abreaction (reliving) of significant childhood trauma. Depending on the intensity and nature of the abuse, and the degree of impact on usual developmental processes, the treatment process commonly extends over a period of years. The use of medication is highly problematic and at most functions as a supportive tool. Adjunctive therapies (art, dance, etc.) may be incorporated into the primary treatment.
Many different outlines of the treatment process have been offered. My own description of the usual (and often overlapping) phases of treatment may be described as 1) diagnosis and establishing rapport; 2) "mapping" the personality system and understanding the psychological dynamics and relationships between personalities, 3) therapeutically processing the trauma, including planned abreaction (reliving) sessions, 4) working toward resolution of the trauma and a more unified experience of life.
There is little data available on prognosis for MPD, partially due to the length of the treatment process. The general consensus is that the prognosis is good if the patient is able to remain in the therapy process for the extended period of time needed.
Diagnostic criteria for 300.14 Dissociative Identity Disorder