FT‐01‐04: Major neurocognitive disorder: Case of Alzheimer's disease

The diagnoses of dementia and Alzheimer’s disease (AD) have served the clinical community well over the past two decades. In general, there has been good agreement between the clinical diagnosis of dementia, particularly AD, and subsequent pathological confirmation. However, as research has progressed, the addition of neuroimaging and chemical biomarkers has now made it possible to suggest a diagnosis of some dementias in their prodromal states. As such, DSM V is considering two categories of cognitive impairment, minor neurocognitive disorder (NCD) and major NCD. Major NCD will include the previous definition of dementia modify and expand upon it. In general, major NCD will include impairment in generally two or more cognitive domains of at least moderate severity with a corresponding loss of independence. The degree of cognitive impairment will approximate the lower 5th percentile of performance relative to appropriate normative data and will be accompanied by a history of a decline in cognition from the subject, informant or as determined by a clinician. The degree of impairment will be sufficient to compromise daily function. The type of major NCD will then be characterized by putative etiology, e.g., degenerative such as AD, frontotemporal dementia, dementia with Lewy bodies or Huntington’s disease, vascular, traumatic brain injury, HIV and other categories. The etiology will be derived from the history, physical exam and diagnostic testing. The key proposed changes include the deletion of the requirement of a memory impairment for major NCD and more definitive guidelines for cognitive function. This broad category of impairment will complement minor neurocognitive disorder.