Recent upward trends in dementia incidence in the UK have reversed previous declines, and that trajectory seems set to continue, according to research led by University College London (UCL).
The new estimates suggest that by 2040, as many as 1.7 million people in England and Wales could be living with dementia — more than 40% higher than previous forecasts.
The study, published in The Lancet Public Health, analysed data from the English Longitudinal Study of Ageing gathered over nine waves between 2002 and 2019, representing 90,073 person observations of participants aged 50 years or more living in private households in England. These data were used to project the future dementia burden based on estimated incidence trends.
Dementia Rates Declined, Then Increased Again
Dementia incidence decreased by 28.8% between 2002 and 2008, compatible with previous studies based on data up to 2010 that had shown incidence declining in high-income countries. However, rates then increased again, by 25.2% between 2008 and 2016.
The team explained that a previous modelling study also led by UCL and published in The BMJ in 2017 had projected that the number of people with dementia in England and Wales would increase by 57%, from 0.77 million in 2016 to 1.2 million in 2040. However, the new study suggests that this figure could be as high as 1.7 million, which is 42% higher than the previous estimate.
Detailed analysis by age, sex, and educational attainment showed similar nonlinear patterns in dementia incidence across all subgroups. However, there were "notable disparities" and "widening inequalities" between education groups. Participants with lower educational attainment had a slower decline in 2002-08 and a faster increase after 2008.
If overall incidence continued to increase as fast as that observed between 2008 and 2016, the researchers predicted that there would be 1.7 million people with dementia in England and Wales by 2040 — approximately twice the 2023 number. This compares with an estimate of 1 million people being affected, assuming dementia rates continued to decline as they had prior to 2008.
Future Burden on Health and Social Care
"It is shocking to think that the number of people living with dementia by 2040 may be up to 70% higher than if dementia incidence had continued to decline," said lead author Dr Yuntao Chen, DPhil, a research fellow in UCL's Institute of Epidemiology and Health Care. "Not only will this have a devastating effect on the lives of those involved, but it will also put a considerably larger burden on health and social care than current forecasts predict."
Principal investigator Eric Brunner, professor of social and biological epidemiology at the Institute, said that the study "exposed that dementia is likely to be a more urgent policy problem than previously recognised, even if the current trend continues for just a few years. We don't know how long this pattern will continue, but the UK needs to be prepared."
The team pointed out that although increases in dementia were often attributed to an ageing population, their analysis showed that the rate of dementia onset within older age groups is also increasing.
Hilary Evans, chief executive at Alzheimer's Research UK, said the research highlighted "the enormous threat" that dementia posed for the public and the healthcare workforce. Too many people continue to experience unacceptable delays in diagnosis, she said, adding: "Healthcare decision-makers need to wake up."
"Biggest Health and Social Care Issue of Our Time"
Commenting to Medscape News UK, James White, head of national influencing at the Alzheimer's Society, said: "Dementia is the biggest health and social care issue of our time. Statistics from this Lancet Public Health study are a stark reminder that, without action, the individual and economic devastation caused by dementia shows no sign of stopping."
He pointed out that at current rates, one in three people born in the UK today would develop dementia. Timely, accurate diagnosis is vital to enable planning for the future and access to treatment, which is "all the more important now we have exciting disease-modifying treatments for Alzheimer's Disease on the horizon," he said. "If lecanemab and donanemab are approved for use in the UK, people will need a timely diagnosis to access them."
Mr White highlighted that people with dementia are the biggest users of social care, but that the system is often costly, difficult to access, and not tailored to people's needs. The new estimates "make it clear that pressure on our already struggling social care system is only going to increase".
The Alzheimer's Society called on the Government urgently to "invest in the social care workforce" with "a sustainable funding model".
Also commenting to Medscape News UK, Caroline Abrahams, charity director at Age UK, said the new figures show the importance of investment in research to prevent and treat dementia. "We know that many people after diagnosis don't get the follow up support they need," she said.
"As a society we need to do a lot more," she added. "There’s no avoiding the need for more funding for the NHS and social care to meet increasing levels of need."