Signs of Terry Pratchett's dementia hidden in his novels

The National

13-03-2025

Scientists reading between the lines of Terry Pratchett's novels believe they have spotted early signs of the author's dementia years before he was diagnosed. A study of 33 of Pratchett's Discworld books found he used simpler language in his later works, which can be a sign of dementia. The British fantasy writer, who died 10 years ago this week, revealed in 2007 that he had a rare form of Alzheimer's disease. The latest research suggests signs of linguistic decline were evident as early as 1998's The Last Continent. As time went on, Pratchett used less varied nouns, verbs and adjectives in his work, researchers told the New Scientist, despite an increase in the overall word count of his books. "This demonstrates a long preclinical period of dementia and the subtle impairments that aren't necessarily picked up by traditional cognitive tests," Loughborough University researcher Thom Wilcockson told the magazine. Pratchett had a form of the disease called posterior cortical atrophy, which damages the rear of the brain. People living with it tend to have problems with their vision and may struggle with words and numbers, the UK's Alzheimer's Society says. It says the first symptoms tend to occur when people are in their 50s or 60s, but early signs are "often subtle" and do not immediately prompt a diagnosis. Pratchett was 59 when he was diagnosed, saying he could no longer type and had given up his driving licence. He continued writing and his 41st and final Discworld book, The Shepherd's Crown, was published in 2015, six months after his death at the age of 66. He also donated money to Alzheimer's research in the hope a cure would be found before he died. Marking the anniversary of his death, Pratchett's former assistant Rob Wilkins said the author "indisputably lives on" in the minds of his readers. "While his words live on, so does Terry, and that will be the case, no question, not just for this one decade so quickly gone but for many further decades to come, "he said. Agatha Christie's detective novels have similarly been put under the microscope in the past, by researchers in Canada who suggested she too might have had Alzheimer's. They said the breadth of her vocabulary appeared to have dropped by 15 to 30 per cent towards the end of her life, with more repeated phrases in her work. Researchers found similar trends in the work of the 20th-century novelist Iris Murdoch, who was known to have Alzheimer's when she died in 1999. Her final novel, Jackson's Dilemma, was measured as using the simplest language of all her works.