Rambling and long-winded anecdotes could be an early sign of Alzheimer's disease, according to research that suggests subtle changes in speech style occur years before more serious mental decline takes hold. Scientists behind the work say it may be possible to detect these changes and predict if someone is at risk more than a decade before meeting the threshold for an Alzheimer's diagnosis.
Janet Cohen Sherman, clinical director of the Psychology Assessment Center at Massachusetts General Hospital, presented the findings at the American Association for the Advancement of Science in Boston. She outlined distinctive language deficits in people with mild cognitive impairment (MCI), a precursor to dementia. 'Many of the studies to date have looked at changes in memory, but we also know changes occur in language,' she said.
Sherman cited studies of the vocabulary in Iris Murdoch's later works, which showed signs of Alzheimer's years before her diagnosis, and the increasingly repetitive and vague phrasing in Agatha Christie's final novels. Another study, based on White House press conference transcripts, found striking changes in Ronald Reagan's speech over his presidency, while George HW Bush showed no such decline. Reagan's speech exhibited a decline in unique words, more repetitions, and increased use of fillers like 'thing' or 'basically'.
The researchers compared language abilities of 22 healthy young individuals, 24 healthy older individuals, and 22 people with MCI. In one exercise, participants had to join three words like 'pen', 'ink', and 'paper' into a sentence. Healthy volunteers typically formed simple sentences, while the MCI group gave circuitous accounts. 'They were much less concise... they had a hard time staying on point,' Sherman said. Another test involving ambiguous pronouns, such as 'Fred visited Bob after his graduation', posed particular difficulty for those with MCI.
With 850,000 people with dementia in Britain and numbers expected to reach 1 million by 2025, early detection is crucial. Many drug trials for Alzheimer's have failed, partly because by the time of diagnosis, damage may be irreversible. 'So we are trying to push the detection period back to the very subtle, early changes,' Sherman said.
