Scientists warn that Covid will accelerate ‘dementia pandemic’
Experts point to mounting evidence that the virus can cause long-term brain damage in some patients
The degenerative effect on the brain of coronavirus will add fuel to the “pandemic of dementia” that will affect an estimated 80m by the end of the decade, scientists and psychiatrists have warned.
Alzheimer’s Disease International, the global federation of dementia associations, on Wednesday unveiled a specialist working group to understand better the scale of the problem and recommend ways to combat it.
“We don’t want to scare people unnecessarily,” said Paola Barbarino, ADI chief executive, “but many dementia experts around the globe are seriously concerned by the link between dementia and the neurological symptoms of Covid-19”.
Alireza Atri, a cognitive neurologist and chair of ADI’s medical and scientific advisory panel, continued: “Covid-19 can cause damage and clotting in the brain’s micro vessels, immune dysfunction and hyperactivation, inflammation, and, last but not least, direct viral brain invasion through the olfactory pathways.
“While there is still a way to go in understanding this, we know that anything that diminishes your cognitive reserve and resilience is going to allow neurodegenerative processes to accelerate, which can cause symptoms of neurological disorders, such as dementia, to show earlier.”
There is mounting evidence that Covid-19 can cause long-term brain damage. One piece is that similar biochemical changes are observed in some coronavirus patients and in people with Alzheimer’s — indicating neuronal injury and inflammation.
Another is the growing number of studies showing that many people with so-called long-Covid suffer from cognitive problems including “brain fog” as well as difficulties with memory, concentration and language. In most patients, such symptoms are expected to resolve themselves over time but the fear is that it may tip some into progressive dementia.
Besides formal scientific studies, clinicians such as Atri and Gill Livingston, professor of psychiatry at University College London, say they have noticed more patients whose dementia is progressing unexpectedly fast after coronavirus.
To make matters worse, Livingston said, “increased isolation because of Covid and social distancing is itself a risk factor for dementia. People are missing the cognitive stimulation that can help delay the onset of symptoms.”
Epidemiologists point out that Covid-19 would not be unusual among viral infections in causing progressive neurological disorders. The 1918 Spanish flu increased survivors’ long-term risk of developing Parkinson’s disease by a factor of two to three, Barbarino pointed out.
Some 55m people are currently living with dementia, according to World Health Organization estimates, which is predicted to rise to about 80m by 2030 as the elderly population increases.
Though it is too soon to quantify the exact effect of Covid-19 on future dementia cases, “it could have a large impact”, said Atri, who is also director of the Banner Sun Health Research Institute in Arizona. “This is a nasty, vicious virus and I’m sure it will tip some people over into dementia sooner than would otherwise be the case.”
Barbarino urged “the WHO, governments and research institutions across the globe to prioritise and commit more funding to research and establish resources . . . to avoid being further overwhelmed by the oncoming pandemic of dementia”.