With the specter of Alzheimer's disease or other types of dementia
threatening an aging American society, researchers are urgently looking for
ways to determine who is going to develop such illnesses.
For example, Deborah Barnes, Ph.D., an assistant professor of psychiatry at
the University of California, San Francisco, and the San Francisco Veterans
Affairs Medical Center, and colleagues set out to develop a late-life dementia
checklist. They wanted an instrument that could reasonably stratify adults
aged 65 or older into those with a low, moderate, or high risk of developing
dementia within six years. And that is what their new tool does, they reported
online May 13 in Neurology.
Barnes and her coworkers focused on more than 3,000 individuals aged 65 or
older who had no sign of dementia and who had been evaluated for many factors
known to influence or suspected of influencing dementia susceptibility
risk—for example, demographic variables, medical conditions,
physical-performance measures, lifestyle factors, genetic predisposition, or
the number of prescription medications used. The researchers followed these
individuals for six years to see which ones developed Alzheimer's or another
form of dementia—480 (14 percent) did—and then looked to see which
of the known or possible dementia risk factors would have predicted these
individuals getting Alzheimer's or another kind of dementia. Finally they
assigned points to the most predictive factors and developed a late-life
dementia risk checklist based on the assigned points.
The checklist included poor cognitive test performance (2-4 points), low
body mass index (2 points), older age (1-2 points), one or more copies of the
APOE e4 gene variant (1 point), white matter disease as revealed through a MRI
brain scan (1 point), ventricular enlargement as revealed through a MRI brain
scan (1 point), internal carotid artery thickening as revealed through an
ultrasound scan (1 point), a history of bypass surgery (1 point), slow
physical performance based on time to put on and button a shirt (1 point), and
lack of alcohol consumption (1 point). The checklist had a maximum possible
score of 15 points.
This checklist, the researchers reported, stratified subjects into those
with low, moderate, or high risk of developing dementia. Whereas only 4
percent of subjects with low scores developed dementia over a six-year period,
23 percent of subjects with moderate scores and 56 percent of subjects with
high scores did. Predictive accuracy did not differ by gender, race, or
"It is important to caution that the factors we identified are
predictive, but not necessarily causal," Barnes explained to
Psychiatric News. "[For example,] lack of alcohol consumption
is likely to be a marker for other things, such as worse health status [or]
use of medications for which alcohol consumption is
contra-indicated...." A low body mass index could be an indication that
the disease is already under way (Psychiatric News, May 15).
Such a checklist, Barnes and her colleagues wrote in their report, could
have several uses. It could reassure concerned older individuals whose
dementia risk is low or moderate. It could encourage concerned older
individuals whose dementia risk is high to seek treatment at the earliest
possible stage of disease or to participate in a clinical trial exploring new
intervention or prevention strategies for dementia.
The next step will be to develop a briefer dementia risk checklist, Barnes
told Psychiatric News. "We'd like to develop a tool that could
be administered in a physician's office in 10 minutes at low cost."
The study was funded by the National Institutes of Health and the
University of California, San Francisco's Clinical and Translational Sciences
An abstract of "Predicting Risk of Dementia in Older
Adults" is posted at<www.neurology.org/cgi/content/abstract/WNL.0b013e3181a81636v1>.▪