The power of knowing: Ireland’s quiet revolution of diagnosing Alzheimer’s

Samples, generously donated by our patients, have allowed us to build Ireland’s biggest biobank for neurodegenerative diseases, writes Professor Sean Kennelly

At a time when very few sites in Ireland were routinely doing so, Tallaght University Hospital began using cerebrospinal fluid biomarkers to investigate the biological roots of our patients' symptoms. File photo

For countless families, the first signs of memory loss trigger a slow descent into uncertainty — a painful limbo of unanswered questions about the future. 

For too long, medicine has had too few answers, leaving patients and their loved ones to navigate a confusing and often frightening journey alone. But in Ireland, we are working to end this era of ambiguity. 

Through a quiet revolution in biomarker testing, we are giving people two crucial tools: the certainty of a diagnosis and the power that comes from knowing.

Our journey began at Tallaght University Hospital in 2016. At a time when very few sites in Ireland were routinely doing so, we began using cerebrospinal fluid (CSF) biomarkers to investigate the biological roots of our patients' symptoms. We moved beyond observation and into objective science. 

Very quickly, we saw clear patterns emerging: biological signatures that we understood to be consistent with Alzheimer’s. This was a pivotal moment, shifting the diagnostic process from a probability based on cognitive tests to a certainty based on biology.

Professor Sean Kennelly: 'We must ensure that access to testing, and eventually treatments, is equitable for all, so that as many people as possible can experience the power of knowing.'

Those early clinics became the foundation for something much larger. The samples, generously donated by our patients, have allowed us to build Ireland’s biggest biobank for neurodegenerative diseases. 

This is now a dynamic research engine, constantly growing and giving us the information needed to understand the deep complexities of Alzheimer’s and other memory conditions. 

We are incredibly grateful for our patients' willingness to contribute to this national asset. For many, knowing their samples are helping to improve diagnosis and find future therapies is important in their journey of coming to terms with their own diagnosis, by giving them a role in efforts to defeat this disease.

A common approach

From the beginning, our ambition was national. The work started in our Dublin clinic now serves as a model for a collaborative network of specialist memory clinics in Cork, Galway, and Belfast. 

By working closely together, we are establishing a common approach to taking samples and providing care, sharing best practice to ensure a consistently high standard for every patient, no matter where they live. 

Now, all patients attending any memory service have the opportunity to have their biomarkers tested, with the lab in Tallaght processing samples for many clinicians operating in sites across the Republic of Ireland and Northern Ireland. 

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Ireland is uniquely positioned for this kind of nationwide innovation. 

Our health system, with bodies like the National Dementia Service embedded directly within it, provides the fluidity to adopt new testing approaches and scale them efficiently across the country. 

This structure allows us to be agile, ensuring that breakthroughs can be tailored to our population’s needs and made accessible to all.

The extent of dementia in Ireland

The need for this work is stark. An estimated 40% of people with dementia in Ireland are living without a diagnosis, leaving them and their families to face unanswerable questions as they try to plan for the future. 

In the long absence of disease-modifying treatments, we have allowed this uncertainty to become an unacceptable norm. 

A person with chest pain rightly expects and receives a clear diagnosis for their symptoms from a cardiologist; why should a person with suspected dementia face any less certainty or respect?

Biomarker diagnosis

A biomarker-supported diagnosis provides two essential things: clarity and confidence. As clinicians, it gives us the scientific confidence to make a firm, definitive diagnosis. 

For patients, this certainty is often met with relief. It validates their experience, ends the ambiguity, and gives them and their families a clear path forward to plan their lives and access support. 

The benefits are tangible and life-altering; studies show that patients who receive a specific, biomarker-supported diagnosis are less likely to end up in institutional care and have a lower mortality rate in the following years.

We are on the cusp of a seismic shift. A decade ago, the idea of a simple blood test for Alzheimer’s seemed like science fiction; today, it is very nearly a reality. The next generation of doctors will use biomarker testing as standard, and our previous methods will seem almost Dickensian in comparison. 

Inequality

However, as we look ahead to this new era, we also face a critical challenge. Alzheimer's is a terribly inequitable condition, disproportionately affecting people from disadvantaged backgrounds or with less education, who are more likely to remain undiagnosed. 

We have a profound, collective duty to ensure these powerful new tools close, rather than widen, these existing health inequalities. 

We must ensure that access to testing, and eventually treatments, is equitable for all, so that as many people as possible can experience the power of knowing.

• Professor Seán Kennelly is a consultant geriatrician and Director of the Tallaght Institute for Memory and Cognition in Tallaght University Hospital, and Clinical Associate Professor in Medical Gerontology in Trinity College Dublin.