Participants are needed for a groundbreaking new study, which is hoping to identify the early signs of dementia years before any symptoms develop.

Researchers at Trinity College Dublin (TCD) are aiming to recruit 100 people for the study, which hopes to identify the earliest signs of dementia 20 or 30 years before symptoms, such as confusion and memory loss, develop.

Dementia affects around 55,000 people in Ireland and 48 million people worldwide. These figures are expected to increase significantly in the coming years, due to an ageing population.

The most common type of dementia is Alzheimer's disease. It accounts for 60-70% of all dementia cases, but no new drugs for Alzheimer's have entered the market over the last 15 years and no current treatments can prevent or slow down the disease.

However, by identifying early markers of Alzheimer's, researchers may then be able to design targeted intervention programmes to help delay, or even prevent, the onset of dementia.

This new study, entitled Prevent, aims to detect early features of the risk of developing Alzheimer's in people with no symptoms of the disease.

The research is being carried out by a team at the Global Brain Health Institute (GBHI) at TCD, as part of a large-scale study in collaboration with UK and French researchers.

As part of the Irish research, 100 participants aged 40-59 are to be recruited. They must not have dementia or any significant cognitive problems at the outset. Some may have parents with dementia, while others may not.

The researchers emphasised that while having a parent with dementia is a risk factor for developing the disease, it does not mean a person will develop it.

One of the principal investigators on the study, Prof Brian Lawlor, who is co-director of the GBHI, pointed out that recent research suggests subtle changes in the function and structure of the brain ‘may be detectable during middle adulthood, years before the first clinical signs of dementia become apparent'.

"We believe that mid-life may be a golden time to introduce measures to help prevent the onset of dementia. But we need to know what are the earliest signals that mean that a person is at greater risk of developing dementia if we are to intervene at this stage.

"The Prevent research programme hopes to identify early markers of the disease before symptoms and brain damage occurs, so that we can target these individuals early on with interventions that may delay the onset of the condition," he explained.

The researchers will be looking for subtle, early changes in the neurological, cognitive and brain health of individuals who have no symptoms, but are at risk of developing Alzheimer's disease.

Tests will also be carried out on individuals who have a lower risk of developing the disease based on family history.

During the study, participants will be asked to provide biological samples, such as blood and urine, and complete cognitive, neurological and MRI neuroimaging assessments in the first year, and again, two years later.

According to co-principal investigator, Dr Lorina Naci, an assistant professor of psychology at TCD, the use of brain imaging assessments, particularly MRIs, ‘holds great promise for better understanding of the disease process'.

"They can reveal subtle changes in cognition long before behavioural manifestations, such as memory loss and confusion. A recent report by the US Alzheimer's Association found that early diagnosis could save up to €7.9 trillion by enabling better management of the disease.

"Intervening in mid-life could be game changing as it provides a unique disease-altering window, before substantial damage has occurred. The population-wide early intervention programmes that will follow this study may treat and, ultimately, prevent Alzheimer's disease, the most common form of dementia," she noted.

All of the testing will take place at St James's Hospital and Beaumont Hospital in Dublin. Full details on what is involved for participants in the study are available here.