Sir Terry Pratchett was diagnosed with Alzheimer's two years ago
Scientists at the University of Sussex have revealed that money donated by Sir Terry Pratchett to Alzheimer's research has been of significant help.
The author was diagnosed with a rare form of Alzheimer's in 2007, and donated more than £500,000 last year to the Alzheimer's Research Trust.
Researchers said his donation had allowed them to see how the disease attacks the brain.
They said they hoped it would help in the development of new treatments.
The team of researchers, led by Dr Louise Serpell, has been investigating ways of slowing or halting Alzheimer's disease.
She said: "We urgently need to improve our understanding of what happens in the brain as the disease develops.
"As our knowledge increases, we can target new research towards therapies that can help people with dementia."
Rebecca Wood, chief executive of the Alzheimer's Research Trust, said Sir Terry's support "knows no bounds" and as well as speaking about his own diagnosis, he had "put his money where his mouth is".
Sir Terry, who is patron of the trust, said: "There's only two ways it can go: researchers, with as much help we can give them, may come up with something that reduces the effects of this dreadful, inhuman disease; or we will have to face the consequences of our failure to prevent the final years of many of us being a long bad dream.
"The strain on carers and their support is bad enough now; before very long the effects on the health service and society itself will be unbearable."
More than 22,500 people in Sussex have dementia, a number forecast to increase to 29,712 by 2021, according to the Alzheimer's Research Trust.