One of the earliest detectable changes may be the plaques of Alzheimer's. But scientists don't yet know how their presence predicts the descent into Alzheimer's dementia.
Some physicians worry all the talk about early Alzheimer's and the new biomarker tests is getting ahead of the science — and could unleash a wave of premature, uncertain diagnoses of a devastating disease with no cure.
In the recent Alzheimer's survey, two-thirds of U.S. respondents said if it were available, they would get a medical test that would tell them whether they would get Alzheimer's disease — even before they had any symptoms. In fact, no one is now suggesting healthy people with no symptoms be tested for Alzheimer's. As for older people who are showing subtle signs of mental decline, they need to know that the standard evaluation could be ambiguous, says Brian Carpenter, a psychologist at Washington University in St. Louis. But his research has found that patients evaluated at the university's Alz heimer's Disease Research Center actually became less anxious after diagnosis. So did their caregivers. "People are telling us they appreciate having an explanation for the symptoms that they've been having," says Carpenter. "They can move forward and create a plan for their lives." Just because you are starting to experience some mild symptoms, he says, doesn't mean that you can't continue to do things, even work.
For those with no symptoms who worry they may eventually get Alzheimer's, there is no crystal ball test to foretell the disease.
"It will likely be many years before any test can predict precisely who really will get the disease, and when," says Frances, who has helped establish guidelines to diagnose mental disorders. "In the meantime, there will be lots of continued hype about progress in testing," he says. "The best thing most people can do is simply ignore it. Instead of worrying about Alzheimer's, you should make sure to exercise your mind and body, eat well, don't drink too much, and enjoy life."
Katharine Greider lives in New York and writes about health and science issues.