Alzheimer's research in 'major step' towards blood test
8 July 2014 Last updated at 22:11 BST
British scientists say they have made a major step forward in developing a blood test to predict the onset of Alzheimer's disease.
Research in more than 1,000 people has identified a set of proteins in the blood which can predict the start of dementia with 87% accuracy.
Hugh Pym reports.