Dissociative disorders are so-called because they are marked by a dissociation from or interruption of a person's fundamental aspects of waking consciousness (such as one's personal identity, one's personal history, etc.). Dissociative disorders come in many forms, the most famous of which is dissociative identity disorder (formerly known as multiple personality disorder). All of the dissociative disorders are thought to stem from trauma experienced by the individual with this disorder. The dissociative aspect is thought to be a coping mechanism -- the person literally dissociates himself from a situation or experience too traumatic to integrate with his conscious self. Symptoms of these disorders, or even one or more of the disorders themselves, are also seen in a number of other mental illnesses, including post-traumatic stress disorder, panic disorder, and obsessive compulsive disorder.
Dissociative amnesia: This disorder is characterized by a blocking out of critical personal information, usually of a traumatic or stressful nature. Dissociative amnesia, unlike other types of amnesia, does not result from other medical trauma (e.g. a blow to the head). Dissociative amnesia has several subtypes:
Dissociative fugue is a rare disorder. An individual with dissociative fugue suddenly and unexpectedly takes physical leave of his or her surroundings and sets off on a journey of some kind. These journeys can last hours, or even several days or months. Individuals experiencing a dissociative fugue have traveled over thousands of miles. An individual in a fugue state is unaware of or confused about his identity, and in some cases will assume a new identity (although this is the exception).
Dissociative identity disorder (DID), which has been known as multiple personality disorder, is the most famous of the dissociative disorders. An individual suffering from DID has more than one distinct identity or personality state that surfaces in the individual on a recurring basis. This disorder is also marked by differences in memory which vary with the individual's "alters," or other personalities. For more information on this, see the NAMI factsheet on dissociative identity disorder.
Depersonalization disorder is marked by a feeling of detachment or distance from one's own experience, body, or self. These feelings of depersonalization are recurrent. Of the dissociative disorders, depersonalization is the one most easily identified with by the general public; one can easily relate to feeling as they in a dream, or being "spaced out." Feeling out of control of one's actions and movements is something that people describe when intoxicated. An individual with depersonalization disorder has this experience so frequently and so severely that it interrupts his or her functioning and experience. A person's experience with depersonalization can be so severe that he or she believes the external world is unreal or distorted.
Since dissociative disorders seem to be triggered as a response to trauma or abuse, treatment for individuals with such a disorder may stress psychotherapy, although a combination of psychopharmacological and psychosocial treatments is often used. Many of the symptoms of dissociative disorders occur with other disorders, such as anxiety and depression, and can be controlled by the same drugs used to treat those disorders. A person in treatment for a dissociative disorder might benefit from antidepressants or antianxiety medication.