What is dissociative amnesia?
Dissociative amnesia is one of several dissociative disorders that mentally separate a person from some aspect of their self, often following trauma or severe stress. In the case of dissociative amnesia, individuals are separated from their memories, suffering abnormal memory loss in ways that significantly disrupt their lives. They may forget a specific event, or they may forget who they are and everything about themselves and their personal history.
The person may or may not be aware of their memory loss though they may appear confused. Unlike those who develop medical amnesia after an injury or stroke, however, someone with dissociative amnesia rarely shows concern about their condition. It’s estimated that 1.8 percent of American adults experience dissociative amnesia in a given year.
Types of dissociative amnesia
Cases of dissociative amnesia can vary from one person to another in a few different ways, although there are no distinctive diagnostic types. How and what a person forgets is one way in which the experience can differ:
Localized amnesia. This occurs when a person forgets a period of time or an event. Some people may forget one short episode in their lives, while others lose long periods of time.
Selective amnesia. Selective amnesia occurs when a person has memory loss associated with something specific, such as an aspect of an event or a person.
Generalized amnesia. This is rare and causes a complete loss of memory of one’s personal identity and history.
Dissociative amnesia can also be further categorized by how long it lasts. Some people will regain their memories after a few minutes or a few hours. Others may forget for days, weeks, or months. Rarely a person with this condition will lose memories for years at a time.
There is one specifier for dissociative amnesia. Dissociative fugue was once considered a separate diagnosis, but it is now a specifier, meaning a person with dissociative amnesia may also experience fugue. Dissociative fugue causes a person to leave their usual lives for a period of time and wander or travel, either with purpose or in a bewildered, confused manner. It may last for a day and involve wandering around one’s neighborhood, or it may be more long-term and involve distant travel.
Causes of dissociative amnesia
The primary cause of dissociative amnesia is stress associated with traumatic experiences that the patient has either survived or witnessed. These may include such major life stressors as serious financial problems, the death of a parent or spouse, extreme internal conflict, and guilt related to serious crimes or turmoil caused by difficulties with another person.
Susceptibility to hypnosis appears to be a predisposing factor in dissociative amnesia. As of 2002, however, no specific genes have been associated with vulnerability to dissociative amnesia.
What are the risk factors for dissociative amnesia?
Exposure to traumatic experiences, either a single time or ongoing. This can include
Being in a terrible accident
Physical or sexual abuse
Being the victim of violence.
Symptoms of dissociative amnesia
Symptoms and signs of dissociative disorders include:
Significant memory loss of specific times, people and events
Out-of-body experiences, such as feeling as though you are watching a movie of yourself
Mental health problems such as depression, anxiety, and thoughts of suicide
A sense of detachment from your emotions, or emotional numbness
A lack of a sense of self-identity
The symptoms of dissociative disorders depend on the type of disorder that has been diagnosed. There are three types of dissociative disorders defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM):
Dissociative Amnesia. The main symptom is difficulty remembering important information about one’s self. Dissociative amnesia may surround a particular event, such as combat or abuse, or more rarely, information about identity and life history. The onset for an amnesic episode is usually sudden, and an episode can last minutes, hours, days, or, rarely, months or years. There is no average for age-onset or percentage, and a person may experience multiple episodes throughout her life.
Depersonalization disorder. This disorder involves ongoing feelings of detachment from actions, feelings, thoughts, and sensations as if they are watching a movie (depersonalization). Sometimes other people and things may feel like people and things in the world around them are unreal (derealization). A person may experience depersonalization, derealization or both. Symptoms can last just a matter of moments or return at times over the years. The average onset age is 16, although depersonalization episodes can start anywhere from early to mid-childhood. Less than 20% of people with this disorder start experiencing episodes after the age of 20.
Dissociative identity disorder. Formerly known as multiple personality disorder, this disorder is characterized by alternating between multiple identities. A person may feel like one or more voices are trying to take control of their head. Often these identities may have unique names, characteristics, mannerisms and voices. People with DID will experience gaps in memory of everyday events, personal information and trauma. Women are more likely to be diagnosed, as they more frequently present with acute dissociative symptoms. Men are more likely to deny symptoms and trauma histories, and commonly exhibit more violent behavior, rather than amnesia or fugue states. This can lead to an elevated false-negative diagnosis.
Complications of dissociative amnesia
A number of complications are associated with dissociative amnesia. These can range from mild to serious and should be watched for. They include:
Thoughts of suicide
Attempting to harm yourself – including cutting, mutilation, etc.
Post-traumatic stress disorder (PTSD)
Relationship and work issues or difficulties
Illegal drug use
Seizures (not due to epilepsy)
Some people who experience dissociative amnesia may end up missing or may be found wandering in unfamiliar areas.
Diagnosis and test
If symptoms of dissociative amnesia are present, the doctor will begin an evaluation by performing a complete medical history and physical exam. Although there are no lab tests to specifically diagnose dissociative disorders, the doctor might use various diagnostic tests, such as neuroimaging, electroencephalograms (EEGs), or blood tests, to rule out neurological or other illnesses or medication side effects as the cause of the symptoms. Certain conditions, including brain diseases, head injuries, drug and alcohol intoxication, and sleep deprivation, can lead to symptoms similar to those of dissociative disorders, including amnesia.
If no physical illness is found, the person might be referred to a psychiatrist or psychologist, health care professionals who are specially trained to diagnose and treat mental illnesses. Psychiatrists and psychologists use specially designed interview and assessment tools to evaluate a person for a dissociative disorder.
Treatment and prognosis of dissociative amnesia
The main type of treatment used to help someone restore memories and cope more healthfully with trauma is therapy. There are no medications approved for treating amnesia. Therapies may vary depending on the needs of the patient, but the general goals are to restore memories, to process and manage emotions related to trauma, to develop healthy coping skills, and to improve overall life functioning. Some types of therapy and treatment strategies used to meet these goals are:
Cognitive-behavioral therapy (CBT). CBT is the backbone of modern therapy and can be adapted for patients who need to process trauma. The focus is on recognizing and shifting negative thoughts, reactions, behaviors, and emotions. It helps patients face negative memories and work through them.
Dialectical behavior therapy (DBT). DBT is a modified form of CBT that was originally developed to treat personality disorders but that is also often used for trauma-focused therapy. It includes the practice of mindfulness, accepting events and emotions, learning to tolerate distress, regulating emotions, and learning to better communicate with and relate to other people.
Eye movement desensitization and reprocessing (EMDR). EMDR was developed to help people cope with trauma. A therapist guides a patient through eye movements while recalling traumatic memories. Something about the brain stimulation triggered by eye movements helps to lessen the emotional impact of the memories.
Creative therapies. Supplemental therapies using art, music, drama, animals, and other creative elements help patients to open up and explore their troubling emotions and memories.
Mindfulness and meditation. Also typically supplemental, mindfulness practices, meditation, and relaxation techniques can help patients learn better and more healthful coping mechanisms for stress and painful memories.
Some patients may try clinical hypnosis, which uses focused concentration and relaxation to delve into subconscious memories in an attempt to recall them and process them.
Drug-facilitated interviews. Interviews conducted after a sedative, such as a barbiturate or a benzodiazepine, is given intravenously.
The prognosis for dissociative amnesia is generally positive with treatment. Most people who seek out treatment will recover their memories. They may come back suddenly or gradually over a long period of time. In rare cases, a person will never have their memories restored, but treatment can help improve function and address any other mental health issues.
Can dissociative amnesia be Prevented?
Although it may not be possible to prevent dissociative amnesia, it might be helpful to begin treatment in people as soon as they begin to have symptoms. Immediate intervention after a traumatic event or emotionally distressing experience can help to reduce the likelihood of dissociative disorders.
The following healthy habits can lower your risk of blackouts, head injuries, dementia, stroke, and other potential causes of memory loss:
Avoid heavy use of alcohol or drugs.
Use protective headgear when you’re playing sports that put you at high risk of concussion.
Stay mentally active throughout your life. For instance, take classes, explore new places, read new books, and play mentally challenging games.
Stay physically active throughout your life.
Eat a heart-healthy diet, including fruits, vegetables, whole grains, and low-fat proteins.