Amnestic disorder

Amnestic Disorder includes the following categories:

• 6D72 Amnestic Disorder
  • 6D72.0 Amnestic Disorder Due to Diseases Classified Elsewhere
  • 6D72.1 Amnestic Disorder Due to Psychoactive Substances Including Medications
    • 6D72.10 Amnestic Disorder Due to Use of Alcohol
    • 6D72.11 Amnestic Disorder Due to Use of Sedatives, Hypnotics, or Anxiolytics
    • 6D72.13 Amnestic Disorder Due to Use of Volatile Inhalants
    • 6D72.12 Amnestic Disorder Due to Other Specific Psychoactive Substance Including Medications
  • 6D72.Y Amnestic Disorder, Other Specified Cause
  • 6D72.Z Amnestic Disorder, Unknown or Unspecified Cause

6D72 General Diagnostic Requirements for Amnestic Disorder

Essential (Required) Features:

• Prominent memory impairment relative to expectations for age and general level of premorbid neurocognitive functioning, in the absence of other significant neurocognitive impairment.
• The memory impairment represents a marked decline from previous levels of functioning.
• The memory impairment is characterized by reduced ability to acquire, learn, and/or retain new information.
• Evidence of memory impairment is based on:
  • Information obtained from the individual, an informant, or clinical observation; and
  • Substantial impairment in memory performance as demonstrated by standardized neuropsychological/cognitive testing or, in its absence, another quantified clinical assessment.
• The symptoms are not better accounted for by disturbance of consciousness, altered mental status, Transient Global Amnesia (i.e., memory impairment lasting no more than 48 hours with most cases resolving within 6 hours), Delirium, Dementia, Substance Intoxication, Substance Withdrawal or another mental disorder (e.g., Schizophrenia or Other Primary Psychotic Disorder, a Mood Disorder, Post-Traumatic Stress Disorder, a Dissociative Disorder).
• The symptoms result in significant impairment in personal, family, social, educational, occupational, or other important areas of functioning. If functioning is maintained, it is only through significant additional effort (e.g., compensatory strategies).

Note: When Amnestic Disorder is due to a disease, condition or injury classified elsewhere (including Disorders Due to Substance Use), the diagnostic code corresponding to that disease, condition or injury should assigned along with Amnestic Disorder. When the etiological condition is unknown, the diagnosis 8A2Z Disorders with Neurocognitive Impairment as a Major Feature, Unspecified may be assigned in addition to Amnestic Disorder.

Additional Clinical Features:

• Amnestic Disorder may or may not include the inability to recall previously learned information. Recent memory is typically more impaired than remote memory, and the ability to immediately recall a limited amount of information is usually relatively preserved.
• Standardized neuropsychological/cognitive testing or quantified clinical assessment may be needed to determine the magnitude and pattern of other neurocognitive impairment(s) and to differentiate Amnestic Disorder from other Neurocognitive Disorders (e.g., Dementia).
• Subjective reports by the affected individual of impairments in learning, memory, or recall do not always correspond to objective or measurable impairment in these areas because of potential alteration in the individual’s awareness, misperceptions of abilities, or misattribution of the cause/source of symptoms or problems. Similarly, it is possible that individuals with altered awareness of deficits may not acknowledge or report memory impairments that are present.
• If standardized neuropsychological/cognitive testing or quantified clinical assessment is not available, the symptom code MB21.1Z Amnesia, Unspecified may be used provisionally until a quantified assessment can be conducted.

Boundary with Normality (Threshold):

• Normal aging is typically associated with some degree of memory change. A diagnosis of Amnestic Disorder does not apply if performance is consistent with expectations for the individual’s age, based on age-related norms for performance on standardized assessment.
• When memory difficulties consistent with normal aging are present and clinically relevant, the symptom code MB21.0 Age-Associated Cognitive Decline may be used.

Course Features:

• Onset of symptoms can be sudden (e.g., when due to stroke or trauma) or gradual (e.g., when due to psychoactive substances or nutritional deficiencies).
• Symptoms may be relatively stable over time or progressive depending on the underlying causal condition or etiology. In some cases, symptoms may improve over time, depending on the specific etiology and available treatment options.
• When memory impairment worsens progressively over time (e.g., due to an underlying Disease of the Nervous System), Amnestic Disorder may represent a prodrome for Dementia.

Culture-Related Features:

• Performance during clinical assessment may vary according to cultural and/or linguistic factors. When assessing impairment in neurocognitive functioning and activities of daily living, cultural and linguistic factors should be considered and accounted for when possible.
• When standardized neuropsychological/cognitive testing is utilized for determination of neurocognitive impairment, performance should be measured with appropriately normed, standardized tests. In situations where appropriately normed and standardized tests are not available, assessment of neurocognitive functioning requires greater reliance on clinical judgment. (See General Cultural Considerations for Neurocognitive Disorders for additional information and examples.)

Boundaries with other Disorders and Conditions (Differential Diagnosis):

• Boundary with Delirium: Although Delirium often includes memory impairment, it is differentiated from Amnestic Disorder by the presence of disturbances in attention, orientation, and awareness and significant confusion or global neurocognitive impairment, in contrast to the specific and prominent memory impairment seen in Amnestic Disorder.
• Boundary with Mild Neurocognitive Disorder: Unlike Amnestic Disorder, Mild Neurocognitive Disorder is characterized by a mild level of neurocognitive decline with little or no impairment in functioning of everyday skills and tasks. In Mild Neurocognitive Disorder, symptoms are not typically restricted to memory impairment.
• Boundary with Dementia: Amnestic Disorder is characterized by prominent memory impairment relative to expectations for age and general level of premorbid neurocognitive functioning, in the absence of other significant neurocognitive impairment. In contrast, Dementia is characterized by impairment in two or more cognitive domains, which frequently but not always includes memory.
• Boundary with Dissociative Amnesia: Amnestic Disorder is characterized by selective and prominent impairment in the ability to learn and remember new information, usually with relative sparing of memory for previously learned information and past events and experiences. In contrast, Dissociative Amnesia is characterized by inability to recall important autobiographical memories, typically of recent traumatic or stressful events, that is inconsistent with ordinary forgetting and is often preceded by an emotional stressor, conflict, or trauma.
• Boundary with memory symptoms in other mental disorders: Memory impairment may be a presenting feature other mental disorders (e.g., Schizophrenia, Mood Disorders, Post-Traumatic Stress Disorder, Dissociative Disorders). If the memory impairment is better explained by another mental disorder, an additional diagnosis of Amnestic Disorder should not be assigned.
• Boundary with Transient Global Amnesia: In Transient Global Amnesia the memory impairment is temporary (i.e., lasting no longer than 48 hours with most cases resolving within 6 hours) whereas in Amnestic Disorder memory impairment is persistent, although in some cases it may improve with treatment, depending on the etiology.

For presentations characterized by prominent memory impairment relative to expectations for age and general level of premorbid neurocognitive functioning in the absence of other significant neurocognitive impairment whose cause is identified but is not adequately captured by any of the other available Amnestic Disorder categories, the following diagnosis may be appropriate:

6D72.Y Amnestic Disorder, Other Specified Cause

Essential (Required) Features:

• All diagnostic requirements for Amnestic Disorder are met.
• The Amnestic Disorder is presumed to be attributable to an identified cause that is not adequately captured by any of the other available Amnestic Disorder categories.
• This judgment depends on establishing that:
  • The specified cause is known to be capable of producing Amnestic Disorder; and
  • The course of the Amnestic Disorder (e.g., onset, trajectory of symptoms, response to treatment) is consistent with the specified cause.

For presentations characterized by prominent memory impairment relative to expectations for age and general level of premorbid neurocognitive functioning in the absence of other significant neurocognitive impairment whose cause is unknown or unspecified, the following diagnosis may be appropriate:

6D72.Z Amnestic Disorder, Unknown or Unspecified Cause

Essential (Required) Features:

• All diagnostic requirements for Amnestic Disorder are met.
• The cause of the Amnestic Disorder is unknown or unspecified.