The YouGov poll, commissioned by the Alzheimer’s Research Trust, found that 42% of the population – 25 million people – know a close friend, family member or someone else with dementia. 700,000 people in the have the disease.

Terry Pratchett, who was diagnosed with Alzheimer’s in December, recently donated $1 million to the Alzheimer’s Research Trust to help find a cure.

"Alzheimer’s is a nasty disease, surrounded by shadows and small, largely unseen tragedies. I understand the desperation of sufferers and their carers and their hopes for, if not a cure, at least some regime that might help us live with Alzheimer’s. Frankly, I’d eat the arse out of a dead mole if it offered a fighting chance. It was a shock to find out that funding for Alzheimer’s research is just 3% of that to find cancer cures. Right now, one thing we can do is make certain that Alzheimer’s does not remain out in the shadows. Once upon a time, cancer was only spoken of as “a long illness”. When people felt able to talk about it, the battle could begin. The same thing can happen with Alzheimer’s. Before you can kill the demon, you have to say its name.”

"With a force like Terry demanding a drastic increase in dementia research funding, the government must recognise soon that it can no longer put off urgently needed reform.”