Results from an extensive new study suggest that early symptoms of Alzheimer’s disease appear up to 18 years before the disease is officially diagnosed.
Researchers publishing in the journal Neurology gave 2,125 people, average age 73, a test of memory and thinking skills every three years for 18 years. All of the participants were either European-American or African-American and none had been diagnosed with Alzheimer’s when the study began.
During the course of the study, 23% of the African-American and 17% of European-American participants developed Alzheimer’s. Those who scored lowest on the memory and thinking tests during the first year of the study were 10 times more likely to develop the disease.
“The changes in thinking and memory that precede obvious symptoms of Alzheimer’s disease begin decades before,” said study author Kumar B. Rajan, PhD, with Rush University Medical Center in Chicago.