More than 1,000 people with suspected dementia are set to take part in a UK trial of a pioneering blood test that could transform the way Alzheimer’s disease is diagnosed. The test, which detects biomarkers linked to abnormal proteins in the brain, will be used alongside traditional cognitive assessments that often fail to identify the disease in its early stages. Scientists at University College London (UCL), who are leading the study, believe the test could raise diagnostic accuracy from 70% to over 90%.

Recruitment has already begun at a memory clinic in Essex, with 19 further NHS centres expected to join. The test measures a marker called p-tau217, which reflects the build-up of amyloid and tau proteins – the key biological hallmarks of Alzheimer’s. Unlike costly brain scans or invasive lumbar punctures, which only a small minority of patients ever undergo, the blood test offers a cheaper and simpler option at around £100. Researchers will also assess whether providing results more quickly improves decision-making for both doctors and patients.

The trial, known as ADAPT, is supported by Alzheimer’s Research UK, the Alzheimer’s Society and funding from the People’s Postcode Lottery. Professor Jonathan Schott of UCL described it as a “critical step” towards revolutionising dementia diagnosis, especially as new treatments for early-stage Alzheimer’s edge closer to approval.

For families affected, the test could be life-changing. Steven Pidwill, whose wife Rachel was diagnosed nearly a decade ago, said a reliable blood test would be a “gamechanger”, helping people view Alzheimer’s as a manageable condition rather than a taboo. Results from the study are expected within three years.