Dissociative amnesia is included in dissociative disorders . It involves not being able to remember relevant personal information, such as an event or one’s own identity. It usually appears as a consequence of the experience of a highly traumatic or stressful event.

There are five different types of dissociative amnesia, depending on their manifestation. In this article we will know the characteristics of this disorder, its symptoms, causes and possible treatments.

What is dissociative amnesia?

Dissociative amnesia is a type of dissociative disorder that appears as such in the DSM (Diagnostic Manual of Mental Disorders). Only one episode of amnesia is necessary to diagnose it (although more may occur).

Dissociative disorders encompass a series of psychological alterations that involve a disconnection or rupture in the processes of memory, identity, perception and/or consciousness . That is, they imply a lack of continuity in some (or among some) of these aspects or processes of the person.

Symptoms

The main symptom of dissociative amnesia is a significant impairment in the ability to remember important personal information . One or more episodes may occur, although only one is necessary to diagnose dissociative amnesia.

Usually the information that is forgotten is of a traumatic or stressful nature. This inability to remember is too extensive to be explained by ordinary or “normal” forgetfulness. The symptoms cause significant distress to the person or interfere with the person’s life and functioning.

Furthermore, in order to make the diagnosis, this alteration in the ability to remember does not occur exclusively within another mental disorder , such as dissociative identity disorder, dissociative flight, post-traumatic stress disorder (PTSD), somatization disorder, etc.

Amnesia is also not caused by the direct effects of a psychoactive substance (drug) or a drug, nor is it explained by a medical or neurological disease.

Characteristics

The information that is “lost” or forgotten in dissociative amnesia is usually part of the person’s conscious awareness, that is, it is their autobiographical memory that is affected. However, even if the person cannot access this information, it can still influence behavior.

For example, let’s think of a woman with dissociative amnesia who has been raped in an elevator, and who can’t get back up in one even if she is unable to remember the event.

The 12-month prevalence of dissociative amnesia is about 1.8%; it is more common in women (2.6%) than in men (1%).

Causes

Dissociative disorders usually originate as a reaction to an extremely stressful or traumatic situation (a trauma); they arise as a defense mechanism for the person (albeit a maladaptive one), to “protect” them from memories that are too traumatic or difficult to process.

These are responses that are reactive to external situations, but taken to the extreme and dysfunctional ; thus, when these responses become disorders, they logically become maladaptive responses.

In this way, dissociative amnesia is often caused by highly traumatic situations that the person lives through and is unable to process functionally. These traumatic or stressful experiences can be directly suffered (e.g. sexual abuse) or simply witnessed.

Types

Dissociative amnesia can be of five types: localised, selective, generalised, systematised and continuous.

1. Localized Amnesia

Localized amnesia involves being unable to remember a specific event or period of time. They are concrete gaps in memory, and are related to a trauma or stressors . In this case the amnesia may last for hours, days or longer. Usually the forgotten period ranges from minutes to decades, but the characteristic here is that the period is clearly delimited.

2. Selective Amnesia

This second type of dissociative amnesia involves forgetting only certain events (or specific parts of them) for a certain period of time. It can appear in conjunction with the previous one.

3. Widespread amnesia

Here the effect on memory is much greater, and patients can lead to forgetting their own identity and life history . Some of them cannot even access the skills they have learned, and even lose the information they have about the world. Their onset is sudden.

It is less frequent than the previous ones, and more common among war veterans, sexually assaulted people and people who have experienced extreme stress or conflict.

4. Systematic amnesia

In this case the person forgets information of a specific category or nature , for example information about the sound surrounding an event, about a specific person, visual elements, smells, etc.

5. Continuous amnesia

In continuous dissociative amnesia, people forget information from a specific point in time to the present (encompassing the present). That is, there is retrograde (past) and anterograde (present) amnesia.

In this case, most patients are aware (or partly aware) of their memory gaps.

Treatment

The treatment of dissociative amnesia includes psychotherapy and some types of drugs (antidepressants, anxiolytics), the latter being complementary to psychological intervention (ideally, they should be used in this way to facilitate psychotherapeutic work, so that the patient is more relaxed to access it.

One of the objectives of psychological therapy will be that the person can process and understand what he or she has experienced , so work must be done on the event and the psychological consequences it is producing.

People with dissociative amnesia may appear confused and distressed, while others may be indifferent. It will be fundamental to work from empathy and flexibility.

Bibliographic references:

  • American Psychiatric Association (APA) (2014). DSM-5. Diagnostic and statistical manual of mental disorders. Madrid: Panamericana.
  • Belloch, A.; Sandín, B. and Ramos, F. (2010). Manual of Psychopathology. Volume I and II. Madrid: McGraw-Hill.
  • Horse (2002). Manual for the cognitive-behavioral treatment of psychological disorders. Vol. 1 and 2. Madrid. Siglo XXI (Chapters 1-8, 16-18).