New Delhi, June 29: The Indian-origin
scientists said, errors on memory and thinking tests may signal Alzheimer’s up
to 18 years before the disease can be diagnosed.
The changes in thinking and memory that precede obvious symptoms
of Alzheimer’s disease begin decades before.
While we cannot currently detect such
changes in individuals at risk, we were able to observe them among a group of
individuals who eventually developed dementia due to Alzheimer’s.
According to the study, 2,125
European-American and African-American people from Chicago with an average age
of 73 without Alzheimer’s disease were given tests of memory and thinking
skills every three years for 18 years.
Twenty-three per cent of African-Americans and 17 per cent of
European-Americans developed Alzheimer’s disease during the study.
Those who scored lower overall on the memory and thinking tests
had an increased risk of developing the disease.
During the first year of the study, people with lower test scores
were about 10 times more likely to be diagnosed with Alzheimer’s disease than
people with higher scores, with the odds increasing by 10 for every standard
deviation that the score was lower than the average.
“A general current concept is that in development of Alzheimer’s
disease, certain physical and biologic changes precede memory and thinking
impairment. If this is so, then these underlying processes may have a very long
“Efforts to successfully prevent the disease may well require a better
understanding of these processes near middle age.”