Their 20-year study included 241 elderly people who were given regular tests to assess their thinking and cognitive abilities, BBC News reported. Scrutiny of the test results revealed subtle clues associated with later mental impairment.
The researchers found that participants who had more difficulty with language expression, learning and recall tasks went on to develop mild cognitive impairment or pre-dementia.
The study appears in the journal Neurology.
Most dementias are diagnosed only after considerable loss of brain tissue. These findings could help lead to earlier diagnosis of dementia, which is important because treatment is most effective when started early, BBC News reported. (November 2009)