May 30, 2024 – Older people at high risk of Alzheimer’s disease who reported significant memory problems during the past year were more likely to have early signs of the disease in their brains, compared to people who didn’t report major memory changes, according to a new study.
The significant memory changes had also been noticed by the people’s spouses, close friends, or relatives. The new findings point to the importance of asking people and their loved ones about changes in memory function to gauge Alzheimer’s risk, the researchers suggested.
The study results were published Wednesday in the journal Neurology. The study included 675 people with an average age of 72 years old, who didn't have problems with their thinking skills at the start of the study but were considered at risk of Alzheimer's disease. They were all enrolled in other studies that are following people long-term to learn more about how the the disease begins.
The 675 people in the study answered questions about their mental skills and also had PET scans of their brains. For each one of them, a “study partner” also answered questions about the person’s mental skills. A study partner could be a spouse, relative, or friend, and 65% of study partners lived with the people being studied.
The questionnaire asked the people and their study partners questions, such as whether the person being studied:
- Had a substantial decline in memory compared to a year ago
- Was misplacing things more often
- Was relying more on written reminders like shopping lists and calendars, compared to a year ago
The researchers reported that early signs of brain changes aligned with greater self-reported and partner-reported decline in thinking skills.
People in the study also took cognitive performance tests, which measure how well the brain does things like learning, remembering, and paying attention. The tests done on people in the study are considered objective and not based on the their perception of their own cognitive ability. Those objective test results tended to align with the subjective reports from the people in the study and their partners.
Alzheimer’s disease is a progressive condition linked to the death of brain cells over time. For this study, researchers looked for two types of protein buildup in the brain linked to Alzheimer’s disease One protein buildup type is called amyloid plaque, and the other is called tau tangles. Some people in the study were already known to have higher amyloid plaque levels, based on their participation in other research.
Just having the presence of the protein buildup is not cause for an Alzheimer’s disease diagnosis, and not all people who have the brain changes eventually get the disease.
The authors noted that amyloid plaque has already been linked to self-reported and partner-reported decline in thinking skills, but there was not ample evidence about whether the presence of tau tangles was linked to people reporting early problems with their mental skills.
These latest findings reinforce the importance of simply asking about memory complaints, which can be a first sign of preclinical Alzheimer’s disease, said researcher Rebecca E. Amariglio, PhD, a clinical neuropsychologist at Brigham and Women’s Hospital in Boston and an associate professor at Harvard Medical School.
“We now understand that changes in the brain due to Alzheimer’s disease start well before patients show clinical symptoms detected by a doctor,” she said in a statement. “There is increasing evidence that individuals themselves or a close family member may notice changes in memory, even before a clinical measure picks up evidence of cognitive impairment.”
The researchers cautioned that their study mainly included people who were White and highly educated, and that further study is needed among a more diverse group of people over a longer period of time.
