Dissociative Amnesia

Primer

Dissociative amnesia is a disorder characterized by an inability to recall important autobiographical information that is successfully stored in memory and ordinarily would be readily remembered. Dissociative amnesia differs from the permanent amnesias due to neurological damage that prevent memory storage or retrieval in that it is always potentially reversible. This is because the memory remains successfully stored.

Types

  • Localized amnesia is a failure to recall events during a specific period of time (hours, days, months), and is the most common form of dissociative amnesia.
  • Selective amnesia is the ability to recall some, but not all, of the events during a circumscribed period of time. Thus, the individual may remember part of a traumatic event but not other parts. Some individuals report both localized and selective amnesias.
  • Generalized amnesia is a complete loss of memory for one's life history. This is rare. Individuals may forget their personal identity. Some lose previous knowledge about the world (that is, semantic knowledge) and can no longer access well-learned skills.
  • Systematized amnesia, is where an individual loses memory for specific categories of information (e.g., all memories relating to one's friends, a particular individual, or childhood trauma)
  • Continuous amnesia is when an individual forgets each new event as it occurs.

DSM-5 Diagnostic Criteria

Criterion A

An inability to recall important autobiographical information, usually of a traumatic or stressful nature, that is inconsistent with ordinary forgetting.

Note: Dissociative amnesia most often consists of localized or selective amnesia for a specific event or events; or generalized amnesia for identity and life history.
Criterion B

The symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.

Criterion C

The disturbance is not attributable to the physiological effects of a substance (e.g., alcohol or other drug of abuse, a medication) or a neurological or other medical condition (e.g., partial complex seizures, transient global amnesia, sequelae of a closed head injury/traumatic brain injury, other neurological condition).

Criterion D

The disturbance is not better explained by dissociative identity disorder, posttraumatic stress disorder, acute stress disorder, somatic symptom disorder, or major or mild neurocognitive disorder.

Specifiers

Specifiers

Specify if:

  • With dissociative fugue: Apparently purposeful travel or bewildered wandering that is associated with amnesia for identity or for other important autobiographical information.

Scales

Psychometric Scales for Dissociative Disorders

Name Rater Description Download
Dissociative Experiences Scale (DES) Patient The scale is a 28-item self-report questionnaire measuring dissociation in normal and clinical populations. The mean of all item scores ranges from 0 to 100 and is called the DES score. There are two versions of the DES, there is the original DES, and the second version, the DES-II.[1] See also the DES Taxon Calculator to help differentiate between pathological and normal dissociation. DES Download

Pathophysiology

Differential Diagnosis

  • Transient global amnesia (TGA)
    • Migraines are a risk factor for TGA
  • Posttraumatic amnesia due to brain injury (amnesia that occurs in the context of a traumatic brain injury)
  • Dissociative identity disorder
  • Posttraumatic stress disorder
  • Neurocognitive disorders
  • Substance-related disorders
  • Seizure disorders
  • Catatonic stupor
  • Factitious disorder and malingering
  • Normal and age-related changes in memory

Investigations

Treatment

Resources

For Patients

For Providers

Articles
Research