HUNDREDS of people in Scotland are to play a major role in a groundbreaking international project which aims to stop the onset of dementia. Experts at Edinburgh University are leading a 64 million Euro study which it is hoped will transform the way the NHS treats Alzheimer's disease. The research will investigate evidence that the disease starts in the brain decades before symptoms such as confusion and memory loss appear. It will also treat those who appear to be at risk of dementia with drugs to help identify therapies which work to prevent these problems. Professor Craig Ritchie, an expert in the psychiatry of ageing at Edinburgh University, said there is emerging evidence that people who suffer from dementia have had signs of disease in their brain for 30 or 40 years. He compared the illness to a heart attack which results from cholesterol deposits - known as plaques - slowly building in the blood vessels. Professor Ritchie said: "You do not just have a heart attack, you have 30 to 40 years of build up of plaque in your arteries. "There is exactly the same paradigm with Alzheimer's - so brain health in mature life is one of the things we are interested in understanding in more detail." Alzheimer's patients have been found to have abnormal amounts of protein - known as amyloid plaques - and fibres - known as tau tangles -along with a chemical called acetylcholine in the brain. Those who volunteer for the new study, which is aiming to recruit 6000 people over the age of 60 across Europe, will have images taken of their brain. They will also need to give blood samples for very detailed testing and undertake cognitive tests which assess skills such as their memory, planning, judgement and language use. Everyone will be tracked for at least five years and those thought to be at highest risk of developing dementia will be put into drug trials. Professor Ritchie said: "If some of the drugs are not proving to be effective people will be taken off them and put on those which are seen to be effective." It is hoped giving treatment before dementia sets in, will produce better results. Professor Ritchie said: "By the time you get dementia you are at end stage brain failure. There is so much going on in the brain... that giving a silver bullet will have very little impact. It is like asking someone to stop smoking when they have had four heart attacks. It is not going to make a great deal of difference." The study, called Epad, has been launched in Paris this week and will ultimately be boosted by similar research programmes in Canada, the United States and Australia. With a number of experts in the field coming together to work in Scotland, Professor Ritchie said: "Scotland is becoming a leading force in dementia prevention. In the next 10 to 15 years we are going to be recognised as the vanguard or forefront of this global effort." Those recruited to the study in Scotland are expected to come from existing research programmes including Generation Scotland and the UK Biobank which have collected samples and health information from hundreds of thousands of people to aid medical research. Henry Simmons, chief executive of Alzheimer Scotland, said: "We are delighted to see Scotland taking a lead on this Europe-wide approach to Alzheimer's disease research. We also welcome the recent appointment of Professor Craig Ritchie to the Chair of Old Age Psychiatry in Edinburgh as a significant progression in the capacity for Scotland to deliver world-leading research in dementia."