“He insisted that things were changing, but he aced all of our tests,” said Rebecca Amariglio, a neuropsychologist at Brigham and Women’s Hospital in Boston. But about seven years later, he began showing symptoms of dementia. Dr. Amariglio now believes he had recognized a cognitive change so subtle “he was the only one who could identify it.”
Patients like this have long been called “the worried well,” said Creighton Phelps, acting chief of the dementias of aging branch of the National Institute on Aging. “People would complain, and we didn’t really think it was very valid to take that into account.”
But now, scientists are finding that some people with such complaints may in fact be detecting early harbingers of Alzheimer’s.
Studies presented Wednesday at an Alzheimer’s Association conference in Boston showed that people with some types of cognitive concerns were more likely to have Alzheimer’s pathology in their brains, and to develop dementia later. Research presented by Dr. Amariglio, for example, found that people with more concerns about memory and organizing ability were more likely to have amyloid, a key Alzheimer’s-related protein, in their brains.
And, in a significant shift highlighted at the conference, leading Alzheimer’s researchers are identifying a new category called “subjective cognitive decline,” which is people’s own sense that their memory and thinking skills are slipping even before others have noticed.
“The whole field now is moving to this area, and saying ‘Hey, maybe there is something to this, and maybe we should pay attention to these people,’ ” said Dr. Ronald C. Petersen, chairman of the advisory panel to the federal government’s new National Alzheimer’s Project.
Dr. Petersen, director of the Mayo Clinic’s Alzheimer’s center, said preliminary results of a Mayo study of healthy older adults in Minnesota suggested something similar.
“Lo and behold, those who had a concern about their memory in fact had more likelihood” of later developing mild cognitive impairment, an early phase of dementia, he said. He said study participants with memory concerns were 56 percent more likely to be given a diagnosis of such impairment, even when results were adjusted for factors like education, genetic risk and psychiatric issues like anxiety and depression.
“These people are sensing something, and there’s some biological signals that correlate,” Dr. Petersen said. “I think it’s real.”
Experts emphasize that many people with such complaints will not develop dementia. Some memory decline reflects normal aging, they say, and some concerns reflect psychological angst. People who forget what they wanted in the kitchen or the names of relatively unfamiliar people are probably aging normally. People who forget important details of recent events, get lost in familiar places or lose track of book or television plots may not be, especially if they have more problems than others their age.
And much remains unknown about subjective concerns. In some studies, like Dr. Amariglio’s, highly educated people noticed changes more readily, but in other studies, less educated people did. Some studies suggest people who worry more about memory deficits have more dementia risk, but it is unclear if the worry reflects the changes they sense or if worrying itself increases risk. People with family histories of dementia could be reporting problems simply because they know about the disease and its genetic component. And, while a study presented Wednesday found slight correlations between subjective concerns and the highest-risk genetic mutation, ApoE4, that relationship remains unclear.
Experts are not yet suggesting doctors regularly screen people for “subjective cognitive decline” because much more research is needed and no effective dementia treatment now exists.
Dr. Richard Caselli, a neurology professor at the Mayo Clinic in Arizona, said that when patients cited cognitive problems, he ruled out “reversible things,” but did not recommend testing for Alzheimer’s because “if we do a scan and say, ‘Hey, we found some amyloid in your brain,’ there’s really nothing you can do.”