Dissociative amnesia

Two famous cases

The stories of two women with multiple personality disorders have been told both in books and films. A woman with 22 personalities was recounted in 1957 in a major motion picture staring Joanne Woodward and in a book by Corbett Thigpen, both titled The Three Faces of Eve. Twenty years later, in 1977, Caroline Sizemore, the 22nd personality to emerge in "Eve," described her experiences in a book titled I'm Eve. Although the woman known as "Eve" developed a total of 22 personalities, only three could exist at any one time-for a new one to emerge, an existing personality would "die."

The story of Sybil (a pseudonym) was published in 1973 by Flora Rheta Schreiber, who worked closely for a decade with Sybil and her New York psychiatrist Dr. Cornelia B. Wilbur. Sybil's sixteen distinct personalities emerged over a period of 40 years.

Both stories reveal fascinating insights-and raise thought-provoking questions-about the unconscious mind, the interrelationship between remembering and forgetting, and the meaning of personality development. The separate and distinct personalities manifested in these two cases feature unique physical traits and vocational interests. In the study of this disorder, scientists have been able to monitor unique patterns of brainwave activity for the unique multiple personalities.

Persons suffering from dissociative identity disorder (DID) adopt one or more distinct identities which co-exist within one individual. Each personality is distinct from the other in specific ways. For instance, tone of voice and mannerisms will be distinct, as well as posture, vocabulary, and everything else we normally think of as marking a personality. There are cases in which a person will have as many as 100 or more identities, while some people only exhibit the presence of one or two. In either case, the criteria for diagnosis are the same. This disorder was, until the publication of DSM-IV, referred to as multiple personality disorder. This name was abandoned for a variety of reasons, one having to do with psychiatric explicitness (it was thought that the name should reflect the dissociative aspect of the disorder).

The DSM-IV lists four criteria for diagnosing someone with dissociative identity disorder. The first being the presence of two or more distinct "identities or personality states." At least two personalities must take control of the person's identity regularly. The person must exhibit aspects of amnesia-that is, he or she forgets routine personal information. And, finally, the condition must not have been caused by "direct physiological effects," such as drug abuse or head trauma.

Persons suffering from DID usually have a main personality that psychiatrists refer to as the "host." This is generally not the person's original personality, but is rather developed along the way. It is usually this personality that seeks psychiatric help. Psychiatrists refer to the other personalities as "alters" and the phase of transition between alters as the "switch." The number of alters in any given case can vary widely and can even vary across gender. That is, men can have female alters and women can have male alters. The physical changes that occur in a switch between alters is one of the most baffling aspects of dissociative identity disorder. People assume whole new physical postures and voices and vocabularies. One study conducted in 1986 found that in 37 percent of patients, alters even demonstrated different handedness from the host.

Statistically, sufferers of DID have an average of 15 identities. The disorder is far more common among females than males (as high as 9-to-1), and the usual age of onset is in early childhood, generally by the age of four. Once established, the disorder will last a lifetime if not treated. New identities can accumulate over time as the person faces new types of situations. For instance, as a sufferer confronts sexuality in adolescence, an identity may emerge that deals exclusively with this aspect of life. There are no reliable figures as to the prevalence of this disorder, although it has begun to be reported with increased frequency over the last several years. People with DID tend to have other severe disorders as well, such as depression, substance abuse, borderline personality disorder, and eating disorders, among others.

In nearly every case of DID, horrific instances of physical or sexual child abuse-even torture-was present (one study of 100 DID patients found that 97 had suffered child abuse). It is believed that young children, faced with a routine of torture and neglect, create a fantasy world in order to escape the brutality. In this way, DID is similar to post-traumatic stress disorder, and recent thinking in psychiatry has suggested that the two disorders may be linked; some are even beginning to view DID as a severe subtype of post-traumatic stress disorder.

Treatment of dissociative identity disorder is a long and difficult process, and success (the complete integration of identity) is rare. A 1990 study found that of 20 patients studied, only five were successfully treated. Current treatment method involves having DID patients recall the memories of their childhoods. Because these childhood memories are often subconscious, treatment often includes hypnosis to help the patient remember. There is a danger here, however, as sometimes the recovered memories are so traumatic for the patient that they cause more harm.

There is considerable controversy about the nature, and even the existence, of dissociative identity disorder. One cause for the skepticism is the alarming increase in reports of the disorder over the last several decades. Eugene Levitt, a psychologist at the Indiana University School of Medicine, noted in an article published in Insight on the News (1993) that "In 1952 there was no listing for [DID] in the DSM, and there were only a handful of cases in the country. In 1980, the disorder [then known as multiple personality disorder] got its official listing in the DSM, and suddenly thousands of cases are springing up everywhere." Another area of contention is in the whole notion of suppressed memories, a crucial component in DID. Many experts dealing with memory say that it is nearly impossible for anyone to remember things that happened before the age three, the age when much of the abuse supposedly occurred to DID sufferers.

Regardless of the controversy, people diagnosed with this disorder are clearly suffering from some profound disorder. As Helen Friedman, a clinical psychologist in St. Louis told Insight on the News, "When you see it, it's just not fake."

Gale Encyclopedia of Psychology, 2nd ed. Gale Group, 2001.