Dissociative amnesia Health Article

Definition

Dissociative amnesiais classified by the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision, also known as the DSM-IV-TR as one of the dissociative disorders, which are mental disorders in which the normally well-integrated functions of memory, identity, perception, or consciousness are separated (dissociated). The dissociative disorders are usually associated with trauma in the recent or distant past, or with an intense internal conflict that forces the mind to separate incompatible or unacceptable knowledge, information, or feelings. In dissociative amnesia, the continuity of the patient's memory is disrupted. Patients with dissociative amnesia have recurrent episodes in which they forget important personal information or events, usually connected with trauma or severe stress. The information that is lost to the patient's memory is usually too extensive to be attributed to ordinary absentmindedness or forgetfulness related to aging. Dissociative amnesia was formerly called "psychogenic amnesia."

Amnesia is a symptom of other medical and mental disorders; however, the patterns of amnesia are different, depending on the cause of the disorder. Amnesia associated with head trauma is typically both retrograde (the patient has no memory of events shortly before the head injury) and anterograde (the patient has no memory of events after the injury). The amnesia that is associated with seizure disorders is sudden onset. Amnesia in patients suffering from delirium or dementiaoccurs in the context of extensive disturbances of the patient's cognition (knowing), speech, perceptions, emotions, and behaviors. Amnesia associated with substance abuse, which is sometimes called "blackouts" typically affects only short-term memory and is irreversible. In dissociative amnesia, in contrast to these other conditions, the patient's memory loss is almost always anterograde, which means that it is limited to the period following the traumatic event(s). In addition, patients with dissociative amnesia do not have problems learning new information.

Dissociative amnesia as a symptom occurs in patients diagnosed with dissociative fugue and dissociative identity disorder. If the patient's episodes of dissociative amnesia occur only in the context of these disorders, a separate diagnosisof dissociative amnesia is not made.