A New Age of Dementia Diagnostics?

12th September 2025

By Mia Turner, Scientific Communications and PR Intern

Forms of dementia, such as Alzheimer’s Disease, go undiagnosed in more than a third of people over 65 who live with them. But that could be set to change with new developments that could see Alzheimer’s Disease diagnosed through simple blood tests [1].

Alzheimer’s Disease is the most common form of dementia and is characterised by the progressive loss of cognitive function and behavioural abilities. A build-up of two rogue proteins in the brain – amyloid and tau – accumulates over decades and eventually results in the symptoms associated with the disease [2]. Alzheimer’s damages parts of the brain involved in memory formation and retention; hence this often shows as the first symptom in many patients. And eventually it can interfere with a person’s ability to function autonomously day-to-day as many patients lose the ability to walk or eat on their own [3].

Photo by Robina Weermeijer on Unsplash

How does it go undiagnosed in so many patients?

Despite the many advances that have been made in research and treatment of Alzheimer’s, there remains no cure and testing for the disease is primitive. Diagnosis typically involves pen and paper memory tests, brain scans and occasionally a lumbar puncture [4]. Many endure delays of more than three years before they receive a dementia diagnosis. This could be because of systemic issues such as lack of specialist access, age and dementia type. Additionally, having early on-set dementia further extends the average diagnosis time to 4.1 years. This is likely due to symptoms being mistaken for normal ageing as well as low social awareness discouraging people from seeking help [5].

Can this be fixed?

Blood-based biomarkers could be the solution. A blood-based biomarker provides a deeper understanding of a person’s overall health and can be measured by a simple blood test. It should be noted that this is not a new concept: blood tests for Alzheimer’s Disease already exist and have been subjected to extensive trials to demonstrate their efficacy and accuracy in diagnosis. However, evidence is lacking to implement these existing tests into nationwide healthcare in the UK because they haven’t yet been tested on diverse groups of patients here [4].

That could be set to change with a new collaborative project involving Alzheimer’s Research UK and the National Institute for Health and Care Research (NIHR) called the ADAPT trial, which forms part of the Blood Biomarker Challenge [1].

This momentous initiative aims to completely revolutionise dementia diagnosis by bringing diagnostic blood tests into the NHS by 2029. Led by Prof Jonathan Schott and Dr Ashvini Keshavan at UCL, the clinical trial will determine whether a blood test that measures a protein (p-tau217) is able to diagnose Alzheimer’s Disease earlier and more accurately than traditional testing [4].

The ADAPT trial involves people currently referred to 20 memory clinics across the UK, ensuring diverse participants including those with other pre-existing health conditions. It hopes to gather more evidence, determine the tests cost-effectiveness (it costs around £100) and evaluate its effectiveness in the NHS system.

Half of the people in the study will receive their results in three months, whilst the other half will receive them after 12 months – this separation aims to help determine whether the increased speed of results has a practical effect on diagnosis speed. It will also provide further evidence on decisions about further investigations and how this difference may influence the way that patients and doctors interpret and respond to the results [2].

Additionally, a separate trial is being conducted by scientists at the Universities of Oxford and Cambridge as part of the READ-OUT initiative that also contributes to the Blood Biomarker Challenge. Here, a team led by Prof Vanessa Raymont, in association with Dementias Platform UK researchers, is investigating the existing and novel blood tests looking at a range of dementia types, not just Alzheimer’s Disease [1].

What’s next?

Whilst these research initiatives are promising and show great development in this field, built on decades of existing work, there is still much to be done to ensure that a concept like this can be implemented to help patients. Without appropriate government funding and approval, trials like these may not become accessible to benefit the public. As such, there is extensive investment and workforce planning required to institute this radical new diagnostic. Additionally, Alzheimer’s Research UK earlier this year launched a new campaign, Dementia Unseen, to call for action and reform from the UK government over the next ten years – ensuring that clinical trials such as these ones don’t go to waste [4].

Summary

Alzheimer’s Disease affects so many people, whether directly or through those around them. With this new groundbreaking research, it’s hoped that more answers can be given to those who may be waiting for a diagnosis and those in the future that will need one. If deemed a success, trials such as the one being conducted at UCL could become a standard part of Alzheimer’s diagnosis and, as described by Prof Jonathan Schott, “will take us a step forward in revolutionising the way we diagnose dementia.” [2]

References

(1) Blood Biomarker Challenge to “revolutionise” dementia diagnosis [Internet]. Alzheimer’s Society. 2024. Available from: https://www.alzheimers.org.uk/blog/blood-biomarker-challenge-dementia-diagnosis

(2) Walsh F. Alzheimer’s blood test could “revolutionise” diagnosis. BBC News [Internet]. 2025 Sep 10; Available from: https://www.bbc.co.uk/news/articles/cm2ze84e8p1o

(3) National Institute on Aging. What is alzheimer’s disease? [Internet]. National Institute on Aging. National Institutes of Health; 2025. Available from: https://www.nia.nih.gov/health/alzheimers-and-dementia/what-alzheimers-disease

(4) UK trial launches to transform Alzheimer’s diagnosis with simple blood test – Alzheimer’s Research UK [Internet]. Alzheimer’s Research UK. 2025 [cited 2025 Sep 10]. Available from: https://www.alzheimersresearchuk.org/news/uk-trial-launches-to-transform-alzheimers-diagnosis-with-simple-blood-test/

(5) Think it’s just aging? Why dementia is missed for 3.5 years on average [Internet]. ScienceDaily. 2025 [cited 2025 Sep 10]. Available from: https://www.sciencedaily.com/releases/2025/07/250727235823.htm?utm_source=village%20life&utm_campaign=village%20life%3A%20outbound&utm_medium=referral