Functional ("psychogenic") amnesia.

Patients who present with severely impaired memory functioning without a discernable neurological cause typically have experienced one or more severely stressful life events. These patients, who are described as having "psychogenic" or "dissociative" amnesia, typically differ from patients with the neurologic amnestic syndrome in that memory for their personal life histories is much more severely affected than is their ability to learn and retain new information; that is, they have isolated retrograde amnesia. Recent cognitive and brain imaging research has begun to reveal some of the cerebral mechanisms underlying functional amnesia, but this disorder remains best conceptualized as a relatively rare form of illness-simulating behavior rather than a disease. Neuropsychological assessment is often useful in revealing the circumscribed nature of the patient's performance deficits, the spared functions that can be brought to bear in rehabilitation, and the emotional disorders requiring psychiatric treatment. Controlled treatment trials are nonexistent, but case reports suggest that supportive psychotherapy, systematic relaxation training, hypnosis, and sedative/anxiolytic medications are useful in facilitating recovery. These treatments are often combined with a psychoeducational approach that essentially reteaches the patient his or her life story.