SelfhelpMagazine

by Marc D. Feldman, M.D.

Dissociative amnesia is a stripped-down version of dissociative identity disorder (DID; also called multiple personality disorder) and dissociative fugue (see SelfHelpMagazine's article on this subject).

An inability to remember events and behaviors is common to all three. But whereas patients with DID have two or more personality states, and dissociative fugue patients unexpectedly travel, dissociative amnesia patients simply find themselves unable to retrieve important autobiographical information, such as their names and dates of birth.

Amnesia, because of its inherent drama, has long been a staple of entertainment. Movies old (Mirage and Spellbound) and more recent (Overboard and The Long Kiss Goodnight) incorporate amnesia as a plot device. TV soap operas use it constantly to keep viewers hooked, and novels such as Kazuo Ishiguro's The Unconsoled buffet their principal characters with the winds of profound amnesia.

Dissociative amnesia is not caused by a medical problem or by alcohol or drug use. Instead, the loss of memory—the very linchpin of identity—is psychologically induced in these cases. It is far too extensive to be explained by the ordinary forgetfulness that plagues us all and instead seems to arise from trauma or stress.

Dissociative amnesia patients do not behave in a confused or disorganized way. Rather, they retain their IQs, their vocabularies, their skills, and their ability to learn new things. They appear perfectly fine to others even though they themselves are usually aware that they've lost pieces of their memories. Surprisingly, only some get upset by this recognition; the rest are relatively unconcerned about the missing information.

Because dissociative amnesia usually arises out of a highly unpleasant situation or psychological conflict, it, like fugue, seems to increase during times of war and natural disasters. But severe interpersonal conflicts can provoke the amnestic episodes too.

Degrees of Forgetfulness

The two most common subtypes of dissociative amnesia are localized amnesia and selective amnesia. In localized amnesia, the individual can't recall the first few hours following a profoundly disturbing event. In selective amnesia, the person can recall some, but not all, of the events during a personally trying time. For example, a soldier with selective amnesia may recall only snippets of the combat missions in which he fought.

Fortunately, a third subtype, generalized amnesia, is much less common than these two. Here, the person has forgotten everything about his or her whole life. Finally, in systematized amnesia, also rare, the patient forgets entire categories of information—such as all information relating to his or her family.

The duration of the events for which there is amnesia is typically hours to days, but in unusual cases it may be years. In one such case, a 55-year-old man insisted in 1984 that it was actually 1945 and that he was 14 years old. He had no idea that he was now a middle-aged man and that his parents and various other family members had died years earlier.

His treatment involved essentially reacquainting him with the intervening four decades. And such treatment requires painstaking work, patience, and extraordinary sensitivity on the part of the therapist. Treatment for bereavement and depression were essential therapeutic extensions.

Unlocking the Mind

Because dissociative amnesia is more likely than fugue to occur multiple times, therapists work hard to intervene before a pattern gets established. We worry that if the original traumatic events, feelings, and impulses are not brought to light, the episodes will snowball and amnesia will become an increasingly persistent protective device in the individual's psyche.

Patients who seek to recapture the forgotten material do sometimes respond to hypnosis or to drug-assisted interviews performed with exceeding care. When hypnosis is used, it is suggested to the patient while in a trance that he or she go back in time to the period immediately preceding the memory loss.

In this way, the goal is not only to restore the lost memory but to identify the life stress that precipitated it. During drug-assisted interviews, a sedating medication is administered intravenously to a patient who is then able to relax enough to talk openly.

Even without such techniques, acute amnesia may resolve over time once the traumatic circumstances have passed. To assist in this process, either the individual must be removed from the upsetting life situation if it is ongoing or steps must be taken to reduce the stress so that further episodes of amnesia are not triggered.

References

Feldman MD, Feldman JM. Stranger Than Fiction: When Our Minds Betray Us. Washington, DC, American Psychiatric Press, Inc., 1998

McNally RJ. Dispelling confusion about traumatic dissociative amnesia. Mayo Clin Proc 2007; 82:1083-1090

McNally RJ. Is traumatic amnesia nothing but psychiatric folklore? Cogn Behav Ther 2004; 33:97-101

About the Author:

Marc D. Feldman, M.D. is the author of "Playing Sick? Untangling the Web of Munchausen Syndrome, Munchausen by Proxy, Malingering, and Factitious Disorder" (2004) and co-author of "Stranger Than Fiction: When Our Minds Betray Us" (1998).