The neurological decline that leads to Alzheimer's disease may begin in middle age and can be predicted with a simple to administer test.
The study, led by Professor David Bunce - Professor of Psychology at Brunel University, West London and a visiting professorial fellow at the Centre for Mental Health Research at the Australian National University (ANU) - has revealed that some apparently healthy adults living in the community aged between 44 and 48 years have minute white matter lesions in areas of their brains similar to those found in persons with Alzheimer's disease later in life.
A further breakthrough generated as part of this research has allowed scientists to more easily predict which individuals may develop these lesions, through a simple-to-administer measure of attention.
The results suggest that the neurological decline thought to lead to the development of Alzheimer's disease may begin much earlier in people's lives than was originally thought.
The work is published in the open-access journal PLoS One.
"Although we cannot be certain that these middle-aged people will go on to get dementia, the results are important for several reasons," said Professor Bunce.
"First, the study is one of the first to show that lesions in areas of the brain that deteriorate in dementia are present in some adults aged in their 40s.
"Second, although the presence of the lesions was confirmed through MRI scans, we were able to predict those persons who had them through very simple to administer measures of attention tests.
"Finally, if the findings are repeated in laboratories elsewhere, the study lays open possibilities for screening, early detection and intervention in healthcare settings. The earlier we can intervene with people vulnerable to eventual dementia, the greater the chances of preventing or delaying the disease onset."