THC Editorial Team April 20, 2021
- What Is Dissociative Amnesia?
- Types, or Subtypes, of Dissociative Amnesia
- Causes and Risk Factors
Although small memory lapses—such as forgetting where you put your keys—can be frustrating, a more serious form of memory loss is called dissociative amnesia: a situation where individuals sometimes fail to recall significant events or names or even who they are.
What Is Dissociative Amnesia?
Dissociative amnesia is one of the three types of dissociative disorders listed in the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (5th edition; DSM-5).1 A dissociative disorder separates an individual from a part of themselves. In the case of dissociative amnesia, a person is separated from a part of their memories.
Professionals refer to dissociative amnesia that is limited to a specific period as thematic. Memory loss that encompasses a large portion of an individual’s past or identity is known as general dissociative amnesia.
Research estimates suggest that about 1%–3% of the global population has this condition, and women are more affected than men.2 Individuals with dissociative amnesia also commonly have other psychological conditions, such as personality disorders.3
A significant difference between dissociative amnesia and traditional amnesia is that a person’s memories still exist in dissociative episodes but are buried as a result of psychological trauma rather than a brain injury or illness.4
What Are Symptoms of Dissociative Amnesia?
The primary symptom of any type of amnesia is memory loss. Affected memories can be of past events or of personal information regarding the individual’s identity.
The cause of memory loss experienced with dissociative amnesia is not physical. Instead, memory loss occurs because of some type of psychological stress. Memories remain, but they are buried so deeply that they are inaccessible.2 Such memory loss may occur after a person experiences traumatic events such as natural disasters, violent crime, or war.
Other symptoms of dissociative amnesia may include confusion, anxiety, and depression unattributable to another condition or to substance use.
Unlike people who have traditional amnesia, where memories are unlikely to be recovered, those who have dissociative amnesia may recover their memories either in a trickle or all at once. Dissociative amnesia is a temporary response to a traumatic event and does not usually last long; sometimes it lasts as little as hours or days.5
Types, or Subtypes, of Dissociative Amnesia
Formerly called psychogenic amnesia, dissociative amnesia can be classified into three types: thematic, general, and fugue. Genetic and environmental factors that contribute to dissociative tendencies are possible.6,7
Thematic Dissociative Amnesia
Also referred to as localized amnesia, thematic dissociative amnesia occurs when someone cannot recall memories from a specified time period or past event. For example, if an individual experienced a bombing, they may have no memory about that specific moment but can recall the details from before and after the event.
General Dissociative Amnesia
Extremely rare, general dissociative amnesia involves an all-encompassing loss of memory regarding the past or a person’s complete identity. It may also involve the loss of semantic and procedural memories, which are types of long-term memory that process ideas and concepts about common knowledge and how to perform actions or skills, respectively.
In a dissociative fugue, the individual cannot remember anything about their personal history or identity. This person may wander around in a state of confusion. In extreme cases, the individual may move to a new location and take on a new identity if the fugue persists for more than a few hours.8
Causes and Risk Factors of Dissociative Amnesia
The most common reason someone may develop dissociative amnesia is experiencing a traumatic event.9 People develop dissociative amnesia when their minds try to protect them from painful memories; therefore, people who have experienced traumatic events are more likely to develop dissociative amnesia. Examples of traumatic events that might trigger this condition include the following:
- natural disasters
- being the victim of a crime, trauma, or abuse
- excessive stress related to relationships, finances, or employment
- witnessing a traumatic event or crime
Additionally, some people may have a genetic predisposition for developing this condition.10 Researchers have found that changes in the brain related to dissociative amnesia can occur in families. Imaging studies have revealed changes in the composition of brain matter in the right temporal and frontal cortices among people who have experienced dissociative amnesia.11
How Is Dissociative Amnesia Diagnosed?
If a person experiences any type of memory loss, a general medical practitioner will perform a complete physical examination that may include brain imaging scans to rule out any physical cause for memory lapses. The doctor may also inquire about a person’s medications, sleep history, and history with drug or alcohol abuse or conduct neuroimaging exams to ascertain whether something else has caused the memory problems.
After this initial assessment, the individual will be referred to a qualified mental health professional. This type of doctor uses interviews and assessment tools to determine if a diagnosis of dissociative amnesia is appropriate. Some of these assessment and interview tools are the Steinberg Dissociative Amnesia Questionnaire (SDAQ), the Dissociative Experiences Scale-II (DES-II), and the Structured Clinical Interview for DSM Dissociative Disorders (SCID-D).12,13
The SDAQ evaluates the severity of depersonalization, derealization, identity confusion, identity alteration, and the distress or dysfunction caused by these symptoms. The DES-II evaluates memory loss, depersonalization, and how absorbed or preoccupied an individual may be by something. The SCID-D involves a structured clinical interview that serves as a diagnostic tool for personality disorders.12,13
Treatments for Dissociative Amnesia
Many cases of dissociative amnesia are extremely brief and may resolve spontaneously if the memories are triggered by other events. However, a variety of treatments can be very effective at helping individuals recall their painful memories in a safe environment while providing support and improving the person’s coping skills.
Several types of psychotherapy can help people effectively determine the root of their issue with dissociative amnesia. Some of these therapies are cognitive behavioral therapy (CBT), family therapy, dialectic behavioral therapy, eye movement desensitization and reprocessing (EMDR), and creative therapies, such as music therapy and art therapy, which have shown promise in helping those affected to deal with past traumatic events.14
Meditation and relaxation create a more relaxed state of mind in which the affected individual may more easily control negative emotions and more effectively recall past events.15,16,17
Although professionals have not yet identified a medication that can cure dissociative amnesia, antidepressants and antianxiety medicines can help with mental health symptoms among those affected.
Additionally, certain medications, such as barbiturates, can be effective in putting a person in a relaxed state to better recall these memories during special counseling sessions.15,18
When performed by a skilled provider, hypnosis can help individuals access subconscious thoughts. Under hypnosis, a person becomes relaxed and can thus better focus on recalling missing information while maintaining a calmer state of mind.
Hypnosis may be a preferred treatment of choice for some providers, as they believe that repressed memories are a type of self-hypnosis that is designed to protect the individual from painful events.2