An older person's own sense of mental decline may be the first sign that they will eventually slip into dementia, according to a panel of experts at the Alzheimer's Association International Conference, concluding here Thursday.
That's not to say that every time someone forgets his car keys, he should worry he's headed for Alzheimer's. All people forget more often as they age, the researchers said, admitting to their own memory lapses.
More serious, and possibly predictive of eventual Alzheimer's in those over 60: getting lost in familiar surroundings, having trouble following the plot of a TV program or book, or a sense that your memory is worse than friends the same age, said Rebecca Amariglio, a clinical neuropsychologist at Harvard Medical School and Brigham and Women's Hospital. (The Alzheimer's Association has a list of 10 such early warning signs, below.)
"People should trust what they observe about themselves," she said.
Doctors should also take seriously anyone who comes complaining of memory loss, said another panel member, Frank Jessen, a professor of clinical dementia research at the University of Bonn and the German Center for Neurodegenerative Disease. "We should listen to what the patient says first."
Unfortunately, right now, there isn't much medicine can do to reduce the chances that a patient's early warning signs will turn into full-blown disease some years later. But this knowledge is extremely useful for researchers looking to identify people at high risk for developing Alzheimer's.
Drug trials of patients with Alzheimer's have consistently failed, suggesting, researchers say, that medication will work only if given early in the disease — years or decades before someone scores poorly on a cognitive test. But it's been impossible to identify those people, apart from a small group with a known genetic mutation, who are being actively studied.
If vulnerable people can identify themselves, researchers will have an easier time finding subjects to study and will come up with effective medications sooner, Amariglio said. Once there is a drug, self-reported memory concerns might also be used to identify people who should take it, she said.
Amariglio and three other panel members each presented results of new studies that found a connection between self-reported memory decline and eventual brain disease.
Amariglio found brain changes associated with Alzheimer's in patients who were otherwise normal but were concerned about their memory or higher-level thinking. In PET scans of 131 people, most around 73-74 years old, those who reported worse memory than their peers had more beta-amyloid, a protein associated with Alzheimer's, in their brains than a comparison group, as did people who said they were slipping in so-called "executive function" — skills such as prioritizing and organizing.
In another study of American nurses, subjective memory concerns were found more often in those who had a genetic risk factor for Alzheimer's than in those who lacked the ApoE4 gene, said Cecilia Samieri, an epidemiologist at the Research Center Inserm U897 in Bordeaux, France. And those with the gene who complained about their memory were more likely to develop Alzheimer's than those with complaints but not the gene, she said.
The worry-free aren't guaranteed not to get Alzheimer's, the researchers said, but their risks are substantially reduced.
A study of 2,230 mentally healthy Germans found that those who complained of memory problems at 80 were more likely to have those problems at 88 than those without the complaints. But still, half the group neared 90 without memory concerns, said Alexander Koppara, a psychologist in Bonn, Germany.
"There is good news for some elderly people," he said.
10 warning signs of Alzheimer's disease:
• Memory changes that disrupt daily life
• Challenges in planning or solving problems
• Difficulty completing familiar tasks at home, at work or at leisure
• Confusion with time or place
• Trouble understanding visual images and spatial relationships
• New problems with words in speaking or writing
• Misplacing things and losing the ability to retrace steps
• Decreased or poor judgment
• Withdrawal from work or social activities
• Changes in mood and personality