Signs of dementia may be detectable nine years before diagnosis – study

Scientists have discovered that it may be possible to spot signs of dementia as early as nine years before patients receive an official diagnosis.

The findings raise the possibility that, in the future, at-risk people could be screened to help select those who could benefit from interventions, or help identify patients suitable for clinical trials for new treatments.

Researchers at Cambridge University published the study - funded by the Medical Research Council with support from the NIHR Cambridge Biomedical Research Centre - in Alzheimer's & Dementia: The Journal of the Alzheimer's Association.

Dr Richard Oakley, associate director of research at the Alzheimer's Society, said the "important" findings suggested that "for some people who go on to develop Alzheimer's disease, memory and thinking problems can begin up to nine years before they receive a diagnosis".

He added: "This opens up the possibility of screening programmes in the future to help identify people at risk and who may benefit from interventions, and identify more people suitable for clinical trials for new dementia treatments, which are both so desperately needed."

The study's first author, Nol Swaddiwudhipong, said: "When we looked back at patients' histories, it became clear that they were showing some cognitive impairment several years before their symptoms became obvious enough to prompt a diagnosis. The impairments were often subtle, but across a number of aspects of cognition.

"This is a step towards us being able to screen people who are at greatest risk - for example, people over 50 or those who have high blood pressure or do not do enough exercise - and intervene at an earlier stage to help them reduce their risk."