Major and Mild Neurocognitive Disorders

Prevalence

• The prevalence of NCD varies widely by age and by etiological subtype.

• Overall prevalence estimates are generally only available for older populations.

• Among individuals older than 60 years, prevalence increases steeply with age.

• The prevalence of mild NCD is very sensitive to the definition of the disorder, particularly in community settings, where evaluations are less detailed.

• Estimates of the prevalence of mild cognitive impairment among older individuals are fairly variable, ranging from 2% to 10% at age 65 and 5% to 25% by age 85.

Symptoms

Major Neurocognitive Disorder

• Evidence of significant cognitive decline from a previous level of performance in one or more cognitive domains (complex attention, executive function, learning and memory, language, perceptual-motor, or social cognition) based on:

  1. Concern of the individual, a knowledgeable informant, or the clinician that there has been a significant decline in cognitive function.

  2. A substantial impairment in cognitive performance, preferably documented by standardized neuropsychological testing or, in its absence, another quantified clinical assessment.

• The cognitive deficits interfere with independence in everyday activities (i.e., at a minimum, requiring assistance with complex instrumental activities of daily living such as paying bills or managing medications).

• The cognitive deficits do not occur exclusively in the context of a delirium.

• The cognitive deficits are not better explained by another mental disorder (e.g., major depressive disorder, schizophrenia

Mild Neurocognitive Disorder

• Evidence of modest cognitive decline from a previous level of performance in one or more cognitive domains (complex attention, executive function, learning and memory, language, perceptual motor, or social cognition) based on:

  1. Concern of the individual, a knowledgeable informant, or the clinician that there has been a mild decline in cognitive function.

  2. A modest impairment in cognitive performance, preferably documented by standardized neuropsychological testing or, in its absence, another quantified clinical assessment.

• The cognitive deficits do not interfere with capacity for independence in everyday activities (i.e., complex instrumental activities of daily living such as paying bills or managing medications are preserved, but greater effort, compensatory strategies, or accommodation may be required).

• The cognitive deficits do not occur exclusively in the context of a delirium.

• The cognitive deficits are not better explained by another mental disorder (e.g., major depressive disorder, schizophrenia).