If somebody you know well starts to laugh at unusual or not-very-funny things; or they suddenly want to watch The Benny Hill Show, rather than their usual, more cerebral satirical comedy choices, it could be an early warning sign of dementia.
Researchers at University College London’s Dementia Research Centre have published a study finding that people with some common forms of dementia start to show an altered sense of humour, on average at least nine years before the start of more ‘typical’ dementia symptoms.
The findings were based on research involving 48 people with different forms of frontotemporal dementia and Alzheimer’s disease, compared with 21 older, ‘healthy individuals’.
Friends or relatives of the 48 people with dementia were asked to rate their loved one’s preference for different kinds of comedy and how it had changed over 15 years.
The researchers were particularly interested in how sense of humour can change in frontotemporal dementia (FTD) and Alzheimer’s disease. While Alzheimer’s disease is the leading cause of dementia generally, frontotemporal dementia is the most common cause of dementia in people under the age of 55.
More symptoms than mere memory
The authors of the study say that, unlike in Alzheimer’s disease, memory difficulties are not an early indicator of FTD. Rather, people tend to experience behaviour and personality changes before they develop any problems with their memory.
This research found that these behavioural changes might include laughing at things that others would not find funny – such as a badly parked car or a barking dog – or laughing inappropriately – such as when seeing a child get hurt or watching news of a tragic event on television.
It might also include making jokes that are smutty, vulgar or childish and then wondering why nobody laughs.
The researchers found that people with both behavioural variant FTD and Alzheimer’s disease tended to prefer slapstick humour (think Benny Hill, The Three Stooges, Mr Bean) to satirical (eg Yes Minister) and absurdist humour (eg Monty Python, The Goon Show) when compared with healthy people of a similar age – even if they had previously been big fans of the more sophisticated forms of comedy.
Importantly, the friends and relatives in the study reported seeing these changes an average of at least nine years before the start of more ‘typical’ dementia symptoms such as confusion and memory loss – and up to 13 years before.
Red flag for brain changes
So what does it mean?
The research team at the UCL Dementia Research Centre, led by Dr Camilla Clark, wanted to explore these kinds of behavioural symptoms, to reveal early clues of underlying brain changes and to try to aid diagnosis
“We’ve highlighted the need to shift the emphasis from dementia being solely about memory loss,” Dr Clark said.
“These findings have implications for diagnosis – not only should personality and behaviour changes ring alarm bells, but clinicians themselves need to be more aware of these symptoms as an early sign of dementia.
“Humour could be a particularly sensitive way of detecting dementia because it puts demands on so many different aspects of brain function, such as puzzle solving, emotion and social awareness,” she said.
Director of Research at Alzheimer’s Research UK, Dr Simon Ridley, said that this study highlights the importance of looking at other, different symptoms of dementia that impact on daily life and relationships, other than simply memory loss.
“We need to see larger studies, following people for extended periods of time, to understand how and when changes in humour could act as a red flag for underlying brain changes,” he said.