Amnesia Disorder
Amnesia is a condition in which a person is unable to recall parts of his or her memory. In some cases, amnesia occurs because of physical damage to the brain. In other cases, emotional distress can lead to the psychological disorder dissociative amnesia.
What is Dissociative Amnesia Disorder?
Dissociative amnesia, also called psychogenic amnesia or functional amnesia, is a type of psychological disorder in the dissociative classification. Dissociative disorders involve disruption or collapse of memories, consciousness, self-awareness, identity, and perception. With dissociative amnesia, a person cannot recall memories.
Dissociative amnesia can be broken down into two types: global and situation specific. With global amnesia, the patient cannot remember anything up to the point of amnesiac onset. In some cases, patients also lose their abilities to perform certain learned skills like reading. With situation-specific amnesia, the patient only loses memory of events related to a traumatic event.
Dissociative amnesia only occurs from psychological causes, not physical causes such as brain damage. The main difference with dissociative amnesia and general amnesia is that the memories still exist in the person’s brain. Thus, the memories can be triggered or resurface. Patients with dissociative amnesia will be able to form new memories.
How Common is Dissociative Amnesia Disorder?
Since women are at higher risk of sexual abuse, they are also more likely to develop dissociative amnesia.
Studies show that situation-specific dissociative amnesia is common amongst the general population. In one study, 32% of people who had undergone a traumatic experience had some degree of dissociative amnesia. Because dissociative amnesia is brought on by traumatic events, it is more common amongst groups of people subject to trauma. For example, people in war-ravaged areas are likely to have high incidences of dissociative amnesia. Soldiers in battle are also likely to experience dissociative amnesia. In the US, dissociative amnesia is more common amongst women. This could be due to the fact that women are more frequently the victims of sexual abuse in the US.
Symptoms
Symptoms of dissociative amnesia are not mere forgetfulness. Rather, symptoms include complete blanks in memory. The memory loss typically comes on immediately after the traumatic situation. It is also common for people with dissociative amnesia to feel confused, depressed or anxious.
Causes
The formation of memories is a biological process which occurs in the brain. The brain is constantly retrieving information and storing it. If a person is put under a great deal of stress, the stress could interfere with the way that the brain stores memories. Studies show that dissociative amnesia is more likely to occur if the stress occurs during childhood and is long lasting. For example, children who experience repeated sexual abuse are more likely to experience dissociative amnesia related to the event than adults who experience sexual abuse once.
Diagnosis
There is no specific diagnosis procedure for dissociative amnesia. Generally, the patient’s statement of memory loss is enough to qualify for a diagnosis of amnesia. To be sure that the amnesia is psychological rather than physical, a doctor may perform brain imaging scans and blood work.
Diagnosing dissociative amnesia has been somewhat controversial in the medical community because many homicidal criminals have used it as a courtroom defense for their actions. Approximately 30-65% of people on trial for murder will claim that they cannot remember the event or part of the event. Certain brain scans which use functional magnetic resonance imaging may be able to show unusual brain activity in people with dissociative amnesia, which can make diagnosis more accurate. Some experts are working on cognitive tests which would be able to identify true dissociative amnesia from faked dissociative amnesia.
Treatments
Unlike with physiological amnesia, dissociative amnesia can be treated. Certain therapies can help the patient recall the blocked memories. However, there have not been any reputable studies on the effectiveness of treatments for dissociative amnesia.
Some therapy methods will use relaxation techniques to help the patient recall memories. These techniques could include hypnotism and/or medications like a benzodiazepine. Some therapists will analyze dreams for clues to the patient’s blocked memories. Another psychoanalytic approach to treatment of dissociative amnesia involves putting a patient in a stressful situation in attempt to trigger memories of the trauma.
Many experts agree that psychotherapy cannot be used for treating dissociative amnesia. Rather, the memories will spontaneously be recalled. Usually, the recall will be triggered by some sort of stimulus which is related to the traumatic event. By talking to family members or people with knowledge of the blocked memories, a therapist may be able to help the patient trigger memories.
References:
American Psychiatric Association. (2000). Diagnostic and Statistical Manual of Mental Disorders (Revised 4th ed.). Washington, DC: Author.
Joseph, Rhawn. “The Neurology of Traumatic ‘Dissociative’ Amnesia. Commentary and Literature Review.” Reprinted from Child Abuse & Neglect 23, 715-727, 1999. Web. <www.brainmind.com>.
Leong, Stephanie, Wendi Waits, and Carroll Diebold. “Dissociative Amnesia and DSM-IV-TR Cluster C Personality Traits.” Psychiatry 3.1. (January 2006): 51-55
