The bestselling author Terry Pratchett today announced a donation of nearly £500,000 for research into Alzheimer's disease, three months after he was diagnosed with the condition.

Speaking at an Alzheimer's conference, the writer of the Discworld fantasy books condemned the "shameful" lack of funding for the disease.

©David Levenson/Getty
Author Terry Pratchett

Pratchett said he wanted to "kick a politician in the teeth" over the patchy provision of treatment for thousands of Alzheimer's sufferers.

The disease affects 700,000 people in the UK, but only £11 is spent per person every year on research, compared to £289 for each cancer patient.

"There's nearly as many of us as there are cancer sufferers, and it looks as if the number of people with the disease will double within a generation," Pratchett told the Alzheimer's Research Trust conference in Bristol.

"It's a shock and a shame, then, to find out that money for research is 3% of that which goes to find cancer cures.

"Perhaps that is why, for example, I know three people who have successfully survived brain tumours but no one who has beaten Alzheimer's."

He contrasted the care he expected to receive with that given to his father, who died of cancer.

"I'd like a chance to die like my father did - of cancer, aged 86. Before he went to spend his last two weeks in a hospice, he was bustling around the house, fixing things.

"He talked to us right up to the last few days, knowing who we were and who he was. Right now, I envy him. And there are thousands like me, except that they don't get heard."

The author, who has sold more than 55 million books worldwide and recently published the 36th book in his Discworld series of humorous fantasy novels, is donating £494,000 ($1m) to the Alzheimer's Research Trust.

He hit out at a shortage of Alzheimer's specialists, and said he was paying for treatment with the Alzheimer's drug Aricept because he was too young to have the treatment for free.

He said: "For those of us with early onset in particular, it's more of a series of skirmishes. My GP is helpful and patient, but I don't have a specialist locally.

"The NHS kindly allows me to buy my own Aricept because I'm too young to have Alzheimer's [treatment] for free, a situation I'm okay with in a want-to-kick-a-politician-in-the-teeth-kind-of-way."

Pratchett announced in December that, at the age of 59, he had been diagnosed with a rare form of early onset Alzheimer's, describing the incurable brain disease as "an embuggerance".

The author said today that having the disease was like stripping "away your living self a bit at a time".

He described Alzheimer's as "a nasty disease, surrounded by shadows and small, largely unseen tragedies".

Pratchett said he took "more supplements than the Sunday papers", and trawled the internet for information about new research and treatments.

"Part of me lives in a world of new age remedies and science, and some of the science is a little like voodoo.

"But science was never an exact science, and personally I'd eat the arse out of a dead mole if it offered a fighting chance."

He reassured his fans that he planned to continue writing, although he joked that "that means I have to stay alive".

"You can't write books when you are dead, unless your name is L Ron Hubbard [the founder of Scientology]," he said.

Pratchett, who has continued to write bestsellers in the two years since he is believed to have first developed the disease, said: "I have a rare variant. I don't understand very much about it, but apparently if you are going to have Alzheimer's it's a good one to have. So, a stroke of luck there then."