Scientists think blood tests could help to diagnose dementia at an earlier stage, which is when treatment is most effective.

Two new drugs, lecanemab and donanemab, have been licensed in the UK but are not available on the NHS in England because the health assessment body NICE said the benefits were “too small to justify the costs”.

But Professor Raymont is optimistic about the future: “We’re in a particularly exciting time at the moment, we’ve had the first two new drugs in 20 years licensed for treatment for Alzheimer’s Disease.

“They’re not available on the NHS yet but new drugs are coming that will hopefully hit the market very soon.”

The Oxford team will also look at more accessible options, like being able to take a finger-prick blood sample at home and send it off in the post.

The trial will aim to recruit a broad range of people including those from minority ethnic groups, the very elderly and people with other medical conditions.