New research suggests that rambling and non-specific speech could be early signs of Alzheimer's disease or dementia.
Not everyone who rambles will go on to suffer from a neurodegenerative condition, but scientists have now identified subtle but measurable changes in speech style that can occur up to a decade before Alzheimer's is officially diagnosed.
In a small sample size, scientists found evidence that people with mild cognitive impairment (MCI) - a type of neurodegenerative condition associated with memory loss - are more likely to use more words than they need to, and take longer to find the right word than their healthy peers.
MCI doesn't always lead to dementia or Alzheimer's, but research suggests people with the condition have a three to five times increased risk of developing dementia than others their age.
"One difference is the mean length of utterance - how many words MCI subjects used versus healthy older subjects," lead researcher Janet Cohen Sherman, from Massachusetts General Hospital, told The Telegraph.
"It was a very significant difference."
Sherman stressed that not everyone who loses their train of thought mid-sentence is at risk of developing a dementia, but it's when speech patterns change suddenly that we need to pay attention to our loved ones.
In fact, she hopes that her team will have a diagnostic linguistic test available within the next decade, that could identify those at risk of developing dementia based on their language patterns, years before other symptoms arise.
"One of the greatest challenges right now in terms of Alzheimer's disease is to detect changes very early on when they are still very subtle and to distinguish them from changes we know occur with normal ageing," Sherman said at the 2017 meeting of the American Association for the Advancement of Science (AAAS) in Boston, as The Guardian reports.
"Many of the studies to date have looked at changes in memory, but we also know changes occur in language."
Researchers had previously noticed these changes in language in the works of popular figures who went on to develop dementia or Alzheimer's, including changes in the writing style of Iris Murdoch in her later books, and the speeches of Ronald Reagan.
"Ronald Reagan started to have a decline in the number of unique words with repetitions of statements over time," said Sherman.
"[He] started using more fillers, more empty phrases, like 'thing' or 'something' or things like 'basically' or 'actually' or 'well'."
To test if this trend was reflected in the general population, the researchers compared the language abilities of 22 healthy young individuals, 24 healthy older individuals, and 22 people with MCI.
These participants were first given exercises where they had to join up three words, for instance, "pen", "ink", and "paper".
The healthy participants were more likely to join the three in a simple sentence - something along the lines of "I write in ink on paper using my pen."
But the patients with MCI gave vague and roundabout, long-winded stories to link the three words - such as talking about going to the shops to buy a pen.
"They were much less concise in conveying information, the sentences they produced were much longer, they had a hard time staying on point and I guess you could say they were much more roundabout in getting their point across," Sherman told The Guardian.
In another experiment, the team asked participants to repeat phrases read out by an investigator.
Complex vocabulary and grammar wasn't an issue for people with MCI, but they struggled when they had to repeat phrases involving ambiguous pronouns, such as "Fred visited Bob after his graduation."
Those are sentences where you have to assign a meaning to pronouns yourself.
To be clear, this is still very early work, so we can't read too much into it just yet - for now the team has only looked at a very small sample size.
The team presented their findings at the AAAS meeting last week ahead of publishing them in a peer-review journal, but until we see a published paper for ourselves, we have to take the results with a grain of salt.
While the jury's still out on this particular warning sign, some early symptoms of dementia that scientists agree we should be looking out for are:
- Confusion about time and place
- Difficulty performing familiar tasks
- Poor or decreased judgement
- Changes in personality or behaviour
- A loss of initiative
- Problems misplacing things
- Problems with abstract thinking
- Memory loss that affects day-to-day function
You can find out more about early signs to look out for here.
Seeing as more people now die from dementia than heart disease in England and Wales - and an effective treatment is still just out of reach - an early way to test for these neurodegenerative condition is more important than ever.