‘Major neurocognitive disorder’ is the old dementia

The hallowed term “dementia” is supposed to be tossed onto the scrapheap of discarded psychiatric nomenclature replaced by “major neurocognitive disorder.”

When the DSM-5 was released in 2013, the American Psychiatric Association gave a year’s grace period for the world to absorb the changes before they take effect. “Dementia” was replaced in the DSM-5 because the term was deemed stigmatizing; the rough translation from the Latin roots is “loss in mind.” Acknowledging that old habits die hard, however, the DSM-5 also states that use of the term is not precluded “where that term is standard.”

The old DSM-IV category of delirium, and amnestic and other cognitive disorder has been replaced in the DSM -5 by the neurocognitive disorder category. Major or mild neurocognitive disorder from Alzheimer’s disease is included under this new category. At the annual meeting of the American Association for Geriatric Psychiatry, highlighted the changes.

“Major neurocognitive disorder” is a syndrome, which includes what was formerly known as dementia. The distinction between it and the new “mild nuerocognitive disder,” previously known as mild cognitive impairment or MCI, is necessarily somewhat arbitrary. Major neurocognitive disorder requires “significant” cognitive decline in one or more cognitive domains as noted by the patients, family member, or clinician along with objective evidence of “substantial” impaired cognition compared to normative test values.

“In contrast, the requirements for mild neurocognitive disorder are ‘mild’ cognitive decline observed by patient, family member, or clinician and ‘modest’ impairment on testing, explained by the professor of psychiatric and health behavior at the Medical College of Georgia, Augusta.

They offered two practical tips in drawing the distinction between major and mild neurocognitive disorder. One is whether the cognitive deficits are sufficiently limited in scope that the patient is still able to function independently in everyday activities.

“If they’re not, moving from[mild] to major,” said professor of psychiatric, neurobiology, and internal medicine at Saint Louis University.

Also, if neuropsychologic testing focusing on memory is performed, he wants to see at least a one standard deviation below the expected age-and education-adjusted norms before calling it objective evidence of “substantial” impaired cognition rising to the level of major nuerocognitive disorder.

Since major neurocognitive disorder is a syndrome, it’s important to try to specify its nature. For the condition to qualify as major neurocognitive disorder from Alzheimer’s disease under the DSN -5, the impairment in cognition must be insidious in onset and gradual in progression. The patients must either have a causative Alzheimer’s disease mutation, which is present in less than 1 percent of all cases of the disease, or else then patient must see three criteria: a decline in memory and learning, plus at least one additional cognitive domain; a steady decline without extended plateaus; and no evidence of mixed etiology involving cardiovascular disease or other disorder.

There’s no requirement that memory impairment be the first affected domain. That’s a bit of a change.

The office- based assessment of neurocognitive disorder as recommended in the DSM-5 includes a careful history and an objective measure of cognitive function such as the Montreal Cognitive Assessment, the Saint Louis University Mental Status Evaluation, and the Mini-Mental State Examination. The patient’s ability to perform activities of daily living should be objectively evaluated, as by the Katz Index of Activities of Daily Living scale or the Barthel Index. A screening neurologic exam should be part of the work-up; this be performed by a primary care physician or a neurologist if the psychiatrist prefers. Since major neurocognitive disorder is a syndrome, the DSM-5 does not require imaging via MRI or CT, although this was a controversial issue during the creation of the DSM-5, and they recommend one-time baseline neuroimaging in order to rule out a tumor, old stroke or, frontotemporal atrophy.

Laboratory test deemed as essential part of the work-up are complete metabolic profile, thyroid stimulating hormone, a complete blood count, urinalysis, and folate.

In addition, many memory clinics now routinely include measurements of vitamin D level, homocysteine,