Sara Tomaszewski-Farias, a professor of neurology at the University of California, Davis, has been awarded a five-year, $3.3 million grant from the National Institute on Aging to study whether cultural differences influence how people perceive age-related cognitive changes. This perceived cognitive aging is called subjective cognitive decline (SCD).
“Subjective cognitive decline refers to a condition in which older adults perceive that their cognitive function is declining, but when tested using neuropsychological tests, their performance is still within normal limits,” explained Tomaszewski-Farias, a leader in the study of cognitive decline in older adults.
Understanding subjective cognitive decline may have important implications for healthcare professionals.
There has been a lot of clinical lore about what we call the “worry well.” These were people who had cognitive complaints but performed well on cognitive tests. They were thought to be depressed or anxious, and their complaints were often ignored. ”
Tomaszewski Farias
However, research indicates that SCD may be a risk factor for more objective cognitive decline. This includes the possibility of mild cognitive impairment and Alzheimer’s dementia. There are three major problems with current SCD research.
- Overlapping symptoms of SCD and depression: People with depression may feel that their memory is impaired. Common symptoms can obscure the correct diagnosis.
- Lack of representation: Research on SCD as a risk for Alzheimer’s disease has primarily focused on highly educated white populations.
- Lack of long-term studies: Most studies were done only at one point in time, rather than over time.
Tomaszewski Farias’ new study examines how SCD is associated with objective cognitive outcomes and risk of dementia in a diverse group of older adults. This study will follow subjects over time to see whether participants with subjective cognitive concerns develop objective cognitive impairment or dementia.
methodology
The study will test approximately 4,000 participants who are at least 55 years old. It will utilize a longitudinal cohort at the UC Davis Alzheimer’s Disease Research Center, where Tomaszewski-Farias is the clinical core leader. The study will also use three cohorts of Kaiser Permanente patients, led by Professor of Neurology and Public Health Sciences Rachel Whitmer (Life After 90, KHANDLE, STAR).
The study will test brain scans and blood samples for biomarkers of Alzheimer’s disease and cerebrovascular disease, in addition to subjective and objective measures of cognitive decline.
Types of subjective cognitive decline that may manifest differently between groups
SCD can be associated with a variety of cognitive concerns.
“The term subjective cognitive decline does not specify the nature or type of cognitive concerns people have,” Tomaszewski-Farias explained. “It may be important to know whether people are primarily reporting memory problems or cognitive changes related to thinking, such as executive function.”
Tomaszewski-Farias elaborates: When people have a lot of memory loss, it can be a sign of early Alzheimer’s disease. On the other hand, people with more executive difficulties, such as those related to multitasking, working memory, and processing speed, may be more likely to have cerebrovascular disease.
To measure subjective cognitive decline, the team uses the Everyday Cognition (ECog) scale. The ECog is a widely used questionnaire developed by Tomaszewski Farias and UC Davis researchers 20 years ago and recently updated. This includes memory questions, such as whether someone has forgotten recent events, and language items, such as having difficulty finding words. You will also be asked about spatial abilities, such as navigation in the environment, and executive functions, such as multitasking and planning daily activities.
The new study asks: Are there different types of subjective complaints associated with specific illnesses? If so, could these complaints help predict future illness?
“We will look at ways to efficiently identify people at high risk for early Alzheimer’s disease and other cognitive decline,” Tomaszewski-Farias said.
Cultural differences and clinical implications
Tomaszewski-Farias said there is much to unpack. “One size probably doesn’t fit all when it comes to identifying subjective warning signs of cognitive decline. It can be highly culture-dependent in terms of how people express what they notice in their cognitive abilities.”
The study will examine how concerned people are about subjective changes and whether they attribute them to normal aging. Research shows that some people find something they missed on cognitive tests. They are noticing internal changes that clinicians cannot yet detect through testing.
It is still unclear how quickly people begin to notice these changes before a clinical diagnosis is made. Research shows that the closest is probably 5 to 10 years before diagnosis.
“We want to be able to better understand or define what kinds of subjective complaints are more significant red flags for clinicians than others,” Tomaszewski-Farias said.
sauce:
University of California Davis Health
