Everyone’s memory fades to some extent as we age, but not everyone will develop Alzheimer’s disease. Screening the most likely people to develop Alzheimer’s remains an ongoing challenge, as some people present only unambiguous symptoms once their disease is advanced.
A new study in JAMA Network Open suggests that one early clue is found in people’s own self-perception of their memory skills. People who are more aware of their own declining memory capacity are less likely to develop Alzheimer’s, the study suggests.
“Some people are very aware of changes in their memory, but many people are unaware,” said study author Patrizia Vannini, PhD, a neurologist at Brigham and Women’s Hospital in Boston. There are gradations of unawareness of memory loss, Dr. Vannini said, from complete unawareness that anything is wrong, to a partial unawareness that memory is declining.
The study compared the records of 436 participants in the Alzheimer’s Disease Neuroimaging Initiative, an Alzheimer’s research institute housed at the University of Southern California. More than 90% of the participants were White, and generally had a college education. Their average age was 75 years, and 53% of participants were women.
Dr. Vannini and colleagues tracked people whose cognitive function was normal at the beginning of the study, based on the Clinical Dementia Rating. Throughout the course of the study, which included data from 2010 to 2021, 91 of the 436 participants experienced a sustained decline in their Clinical Dementia Rating scores, indicating a risk for eventual Alzheimer’s, whereas the other participants held steady.
The people who declined in cognitive function were less aware of slips in their memory, as assessed by discrepancies between people’s self-reports of their own memory skills and the perceptions of someone in their lives. For this part of the study, Dr. Vannini and colleagues used the Everyday Cognition Questionnaire, which evaluates memory tasks such as shopping without a grocery list or recalling conversations from a few days ago. Both the participant and the study partner rated their performance on such tasks compared to 10 years earlier. Those who were less aware of their memory slips were more likely to experience declines in the Clinical Dementia Rating, compared with people with a heightened concern about memory loss (as measured by being more concerned about memory decline than their study partners).
“Partial or complete unawareness is often related to delayed diagnosis of Alzheimer’s, because the patient is unaware they are having problems,” Dr. Vannini said, adding that this is associated with a poorer prognosis as well.
Implications for clinicians
Soo Borson, MD, professor of clinical family medicine at the University of Southern California and coleader of a CDC-funded early dementia detection center at New York University, pointed out that sometimes people are genuinely unaware that their memory is declining, while at other times they know it all too well but say everything is fine when a doctor asks about their current memory status. That may be because people fear the label of “Alzheimer’s,” Dr. Borson suggested, or simply because they don’t want to start a protracted diagnostic pathway that could involve lots of tests and time.
Dr. Borson, who was not involved in the study, noted that the population was predominantly White and well-educated, and by definition included people who were concerned enough about potential memory loss to become part of an Alzheimer’s research network. This limits the generalizability of this study’s results to other populations, Dr. Borson said.
Despite that limitation, in Dr. Borson’s view the study points to the continued importance of clinicians (ideally a primary care doctor who knows the patient well) engaging with patients about their brain health once they reach midlife. A doctor could ask if patients have noticed a decline in their thinking or memory over the last year, for example, or a more open-ended question about any memory concerns.
Although some patients may choose to withhold concerns about their memory, Dr. Borson acknowledged, the overall thrust of these questions is to provide a safe space for patients to air their concerns if they so choose. In some cases it would be appropriate to do a simple memory test on the spot, and then proceed accordingly – either for further tests if something of concern emerges, or to reassure the patient if the test doesn’t yield anything of note. In the latter case some patients will still want further tests for additional reassurance, and Dr. Borson thinks doctors should facilitate that request even if in their own judgment nothing is wrong.
“This is not like testing for impaired kidney function by doing a serum creatinine test,” Dr. Borson said. While the orientation of the health care system is toward quick and easy answers for everything, detecting possible dementia eludes such an approach.
Dr. Vannini reports funding from the National Institutes of Health National Institute on Aging. Dr. Borson reported no disclosures.