Dissociative amnesia is one of several dissociative disorders in which a person forgets key elements of their life, and is therefore divorced from a full understanding of themselves and their current state. It often following trauma or severe stress. In the case of dissociative amnesia, individuals suffer 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.
Dissociative amnesia is not normal forgetting, like misplacing keys or forgetting the name of someone you met once or twice. Symptoms range from forgetting personal information, like one’s own name and address, to blocking out specific traumatic events or even the events of one’s entire life. A person with dissociative amnesia may not remember friends, family members, or coworkers. When a person with generalized dissociative amnesia forgets everything about the self and their life, they may move to a new location and establish a new identity but, when discovered, they don’t know how they got there or why they have no identification. Most cases of dissociative amnesia are temporary, but memory gaps can last anywhere from a few minutes to an entire lifetime. Those with dissociative amnesia may be at greater risk of self-injury and suicide.
The DSM-5 includes the following symptoms for dissociative amnesia:
- The inability to remember important autobiographical information that one would typically be able to recall
- A sense of detachment from self, including identity and emotions
- The forgetting causes distress in daily life, including at work, school, or with friends and family
- The disturbance is not due to substance use, a different mental health disorder, or another medical condition, such as a seizure or brain injury
If a person suffers this dissociative state over a lengthy period, they may suffer long-term memory loss, as well as mood disorders including depression and anxiety. In some severe cases, suicidal ideation can occur.
Past or recent trauma, abuse, accidents, or extreme stress, such as from war or natural disaster, either witnessed or experienced, can cause dissociative amnesia. There may also be a genetic link because individuals with dissociative disorders sometimes have family members with the same condition. Although the symptoms may be similar, dissociative amnesia is not the same as amnesia resulting from brain disease or damage. However, researchers have identified abnormal changes in brainwave activity in people with dissociative amnesia that could lead to a better understanding of traumatic memory loss and more effective disorder-specific treatments.
Dissociative fugue is a subtype of dissociative amnesia. In both types of dissociation, a person can lose awareness of identity, or personal history, or other autobiographical information. The person in a fugue state is often engaged in some form of unexpected travel; he may find himself sitting on a train and not know how he got there. A dissociative fugue may also last longer than a bout of dissociative amnesia. One of the first documented cases of dissociative fugue was that of Ansel Bourne, the real Jason Bourne, who lived in Pennsylvania in the late 1800s.
While there are no evidence-based treatments specifically for dissociative amnesia, psychotherapy and other forms of therapy, such as cognitive-behavioral therapy and dialectical behavioral therapy, are often used to treat the disorder. Techniques such as hypnosis and drug-assisted question-and-answer sessions may help spark the ability to retrieve memories; this can help patients understand how trauma may have caused their amnesia, disrupted their life, and how to resolve their problems to help prevent further trauma in the future. Patients with anxiety or depression can also benefit from medications that target those conditions.
There are no specific drugs for this amnesia. However, co-occurring conditions may need to be addressed. A health professional may need to prescribe antidepressants for mood or anti-anxiety medications for anxiety.
This amnesia often does pass and memory can be recovered. Yet, in some difficult cases, the missing information does not come back.