Society will also have to adjust to this new, more sensitive view of Alzheimer's disease, Foster said.
"If many normal people have Alzheimer's disease, then the stigma of this condition will need to change," he said. "Insurers and the legal system will need to accommodate this new definition."
Alzheimer's disease, the most common cause of dementia among older adults, is estimated to affect 5 million Americans, according to the U.S. Centers for Disease Control and Prevention. The new criteria will expand this number significantly. But the authors of the new criteria said they hope the new guidelines will cut the number of people debilitated by the disease, which is currently the fifth leading cause of death in the United States.
"It is our hope that the advances in preclinical detection of Alzheimer's will enable earlier, more effective treatment, just as nearly all of therapeutic gains in cancer, cardiovascular disease, osteoporosis, and diabetes involve treatment before significant clinical symptoms are present," they wrote.