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A blood test for Alzheimer's disease

Why carry out the research? 

An increasingly ageing population is a wonderful testimony to how research success, particularly in the last century, has led directly to improved health. Unfortunately, this has resulted in increasing numbers of people developing dementia. 

In the UK alone, approximately 700,000 people suffer from dementia, 1 in 14 people over the age of 65 are affected by dementia, and 1 in 3 over 65s will die with some form of dementia. 

The incidence of dementia is expected to rise to 1.7 million within 40 years with dramatic social and economic consequences as our care systems struggle to cope.  

There is enormous unmet need for improved diagnostic tests and treatments for people affected by Alzheimer’s disease. Currently, the only licensed drugs available to patients for the symptomatic relief of memory problems have modest and variable effects and merely temporarily delay progression, if at all. Thanks to recent technological advances, we now have an enormously improved understanding of the clinical, genetic and molecular basis of Alzheimer’s disease as well as normal brain structure and function which is paving the way for new treatments to be developed. 

A major challenge for progressing candidate drugs along the drug development pipeline is the availability of tools to measure their benefits cheaply, sensitively and accurately. Currently, clinical trials for Alzheimer’s disease rely on highly problematic measures such as memory tests and, astonishingly, on the clinician’s impression of whether the patient has deteriorated or not.  

Changes in biological factors or ‘biomarkers’ in the blood are likely to be much more accurate and reliable measures on which to base vital clinical trials. The onset and progression of disease is characterised by changes in the presence and concentration of a variety of specific molecules such as RNA in the blood. With ever advancing technology, we can now measure and analyse these patterns which can then be used as the basis of a simple blood test. 

How is the research being undertaken? 

We are interested in hearing from people who may be able to help with our research. 

Who are we looking for? 

People who are 65 years or older. We are interested in people both with and without a diagnosis of Alzheimer’s disease. Full informed consent will be obtained from participants wherever possible or from next of kin or primary carers.  

What will happen if I agree to take part? 

Participants will be contacted annually and either interviewed by phone or visited in their home. At each visit, they will be asked to provide a blood and urine sample. These will be used to analyse biological molecules including DNA, RNA and protein. Blood samples will be obtained by a routine venepuncture procedure. 

Researchers will also collect information from people and their carers at each visit which will be used to assess cognition, function, behaviour and global severity.  

Some people will be asked if they would like to have an MRI scan. This will allow researchers to investigate brain atrophy and neuronal functional changes which are hallmarks of Alzheimer’s disease.  

Anonymised data and samples from participants will contribute to the project described here and other projects within the biomarker programme at the Department of Old Age Psychiatry. A variety of technologies will be used to investigate different types of biomarker in blood including RNA (for this project), protein and lipids (in related projects) and the best measures in brain which capture atrophy. 


The study is funded by the NIHR Biomedical Research Centre for Mental Health at the Institute of Psychiatry and the South London and Maudsley NHS Foundation Trust, the John and Lucille van Geest Foundation, the Rosetrees Trust, Research in to Ageing, The Inman Charity and the Forest Trust). 


We aim to develop a simple, accurate and inexpensive blood test for Alzheimer’s disease to support the testing of promising treatments in clinical trials.

To achieve this, we will: (a) identify and validate a blood expression biomarker of early Alzheimer’s disease; (b) develop an accurate blood expression biomarker capable of predicting the rate at which a person will deteriorate; and (c) determine the best combination of measures to achieve the most accurate Alzheimer’s disease blood biomarker.