ORLANDO—In May, the term “dementia” is due to be replaced in psychiatric nomenclature by “major neurocognitive disorder.”
When DSM-5 was published in May 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 DSM-5 because the term was deemed stigmatizing; the rough translation from the Latin roots is “loss of mind.” Acknowledging that old habits die hard, however, DSM-5 also states that use of the term is not precluded “where that term is standard.”
The old DSM-IV category of delirium, dementia, and amnestic and other cognitive disorders has been replaced in the DSM-5 by the neurocognitive disorders category. Major or mild neurocognitive disorder from Alzheimer’s disease is included within this new category. At the 2014 Annual Meeting of the American Association for Geriatric Psychiatry, W. Vaughn McCall, MD, and George T. Grossberg, MD, highlighted the changes.
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| W. Vaughn McCall, MD | George T. Grossberg, MD |
Major neurocognitive disorder is a syndrome that includes what was formerly known as dementia. The distinction between it and the new mild neurocognitive disorder, 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 patient, family member, or clinician, along with objective evidence of “substantial” impaired cognition, compared with 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 Dr. McCall, Professor of Psychiatry and Health Behavior at the Medical College of Georgia, Augusta.
Dr. Grossberg 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 he or she is not, I’m moving from [mild] to major,” said Dr. Grossberg, Professor of Neurology and Psychiatry at the Saint Louis University School of Medicine.
Also, if neuropsychologic testing focusing on memory is performed, Dr. Grossberg requires at least 1 SD below the expected age- and education-adjusted normal scores as objective evidence of substantial impaired cognition rising to the level of major neurocognitive disorder.
Because major neurocognitive disorder is a syndrome, Dr. McCall said that it is important to try to specify its nature. For the condition to qualify as major neurocognitive disorder from Alzheimer’s disease per DSM-5, the impairment in cognition must be insidious in onset and gradual in progression. The patient must either have a causative Alzheimer’s disease mutation, which is present in less than 1% of all cases of the disease, or else the patient must meet 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 disorders. “There’s no requirement that memory impairment be the first affected domain. That’s a bit of a change,” Dr. McCall noted.
The office-based assessment of neurocognitive disorders, as recommended in 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. A patient’s ability to perform activities of daily living should be objectively evaluated according to 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 can be performed by a primary care physician or a neurologist if the psychiatrist prefers. Because major neurocognitive disorder is a syndrome, DSM-5 does not require imaging with MRI or CT, although Drs. McCall and Grossberg said that this was a controversial issue during the creation of DSM-5, and they recommend one-time baseline neuroimaging to rule out a tumor, old stroke, or frontotemporal atrophy.
Laboratory tests deemed an essential part of the work-up are a complete metabolic profile, thyroid stimulating hormone, a complete blood count, urinalysis, and folate. In addition, Dr. Grossberg said, many memory clinics now routinely include measurements of vitamin D level, homocysteine, and C-reactive protein in the work-up.
“Vitamin D deficiency is extremely common,” he said. “We’re finding in St. Louis—and I don’t think it’s a whole lot different among the elderly even in Florida, where there’s a lot of sun—that people are afraid of the sun now so they put on a whole lot of sunscreen, preventing vitamin D absorption. We check vitamin D levels routinely in our clinic, and maybe two out of every three older adults we test are low in vitamin D. More and more research shows that deficiency may be related to depression and may also have an effect on cognition. It’s something that’s easily remediable. We give 50,000 IU orally per week for eight weeks, then a maintenance dose of 1,000 to 2,000 IU/day,” Dr. Grossman said.