August 1, 2013

Cognitive complaints, Alzheimer’s risk studied

A study of cognitive complaints in older adults showed that memory concerns from both the patient and an informant was most predictive of converting to Alzheimer’s disease or dementia within three years.

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A study of cognitive complaints in older adults showed that memory concerns from both the patient and an informant was most predictive of converting to Alzheimer’s disease or dementia within three years.

“We’re interested in how we can detect unusual or unhealthy brain changes at their earliest stage, and we found that people who have mutual sources of complaint, from both themselves and a loved one, are at a great risk of developing mild cognitive impairment or Alzheimer’s disease over an approximate two-year period,” said Katherine Gifford, Psy.D., neuropsychology fellow in the Vanderbilt Memory & Alzheimer’s Center and lead author of the study.

Katherine Gifford, Psy.D.

The study, “The source of cognitive complaints predicts diagnostic conversion differentially among nondemented older adults,” was published online July 18 in the journal Alzheimer’s & Dementia.

Researchers leveraged the National Alzheimer’s Coordinating Center’s database of information collected from 34 current and previously funded national Alzheimer’s Disease Centers, supported by the National Institute on Aging. The study included more than 6,000 participants age 55-90 evaluated from 2005-2012.

The analysis revealed that, among the cognitively normal, a combination of both self and informant cognitive complaints was associated with a fourfold risk of progression to dementia or mild cognitive impairment, the earliest clinical stage of dementia. A self complaint or informant complaint alone conferred a twofold increased risk of progression.

Among those with mild cognitive impairment at initial assessment, a combination of both self and informant cognitive complaints was associated with a threefold risk of converting to dementia.

“Ninety-five percent of older adults have some sort of cognitive complaint, so a lot of people will go to their doctor worried but may be dismissed as normal aging,” Gifford said. “I think the results show that a cognitive complaint should be taken seriously, particularly with a mutual complaint. That’s certainly a time when further follow-up or referral to a specialist is warranted.”

Angela Jefferson, Ph.D., director of the Vanderbilt Memory & Alzheimer’s Center, said this research parallels the work of colleagues to identify more effective therapeutic interventions for Alzheimer’s disease.

Angela Jefferson, Ph.D.

“Once these treatments are available, we think they’ll be more effective early in the disease course, so we’re looking at early identification markers.

“There’s an enormous emphasis on biomarkers, but cerebrospinal fluid involves a somewhat invasive lumbar puncture and PET imaging costs thousands of dollars,” Jefferson said.

“We think there needs to be more cost-efficient, easily implemented tools to identify people who are at greatest risk, and this research is a great complementary piece of information.”

For more information about the Vanderbilt Memory & Alzheimer’s Center and to participate in research studies, visit www.vanderbiltmemory.com or contact Outreach and Recruitment Coordinator Stephanie Mayers, Ed.M., at 875-3175 or stephanie.mayers@vanderbilt.edu.
This research was supported by grants from the National Alzheimer’s Coordinating Center, Alzheimer’s Association and National Institutes of Health (AG036697, AG030962, AG034962, AG013846, RR000533, AG016976).