The pandemic has caused sustained harm to the brain health of people aged 50 or over, rapidly speeding up cognitive decline regardless of whether or not they caught Covid, researchers have discovered.
Almost 780 million people were killed or made ill by the coronavirus, according to the World Health Organization. Health experts are now learning more about the indirect effects of the biggest public health crisis in a century.
A study has found that cognitive function and working memory in older adults declined more quickly during the first year of the pandemic between March 2020 and February 2021, even if they were not infected with the virus. The trend continued into 2021/22, suggesting an impact beyond the initial lockdowns.
The research is the largest of its kind to link the pandemic conditions – and the enormous lifestyle shifts triggered by lockdowns and other Covid restrictions – to sustained cognitive decline.
The acceleration in cognitive decline has been exacerbated by a number of factors since the arrival of Covid, the researchers said. These included an increase in loneliness and depression, a fall in exercise and higher alcohol consumption, as well as the effects of the disease itself. The study, led by the University of Exeter and King’s College London, was published in the Lancet Healthy Longevity journal.
Anne Corbett, a professor in dementia research and the lead at Exeter for the Protect study, said: “Our findings suggest that lockdowns and other restrictions we experienced during the pandemic have had a real lasting impact on brain health in people aged 50 or over, even after the lockdowns ended.
“This raises the important question of whether people are at a potentially higher risk of cognitive decline, which can lead to dementia.
“It is now more important than ever to make sure we are supporting people with early cognitive decline, especially because there are things they can do to reduce their risk of dementia later on.” She advised people concerned about their memory to see their GP.
“Our findings also highlight the need for policymakers to consider the wider health impacts of restrictions like lockdowns when planning for a future pandemic response,” she added.
The researchers analysed brain function tests from 3,142 people who took part in the Protect study, which launched in 2014 to gain an insight into the brain function of people over 40 during a 25-year period.
The people assessed were all aged between 50 and 90 and based in the UK. Tests analysed participants’ short-term memory and their ability to complete complex tasks.
The study then looked at all the data collected over the year from March 2019 to February 2020, and compared it with the results from the pandemic’s first year (March 2020 to February 2021) and second year (March 2021 to February 2022).
Analysis showed the rate of cognitive decline quickened in the first year of the pandemic, and was higher among those who had already shown signs of mild cognitive decline before the outbreak of Covid-19.
Writing in the Lancet Healthy Longevity journal, the researchers said: “We found that people aged 50 years and older in the UK had accelerated decline in executive function and working memory during the first year of the Covid-19 pandemic, during which the UK was subjected to three societal lockdowns for a total period of six months.
“Notably, however, this worsening in working memory persisted in the second year of the pandemic, after the social restrictions had eased. The scale of change is also of note, with all groups – the whole cohort and the individual subgroups – showing more than a 50% greater decline in working memory and executive function.”
They cautioned that the study was observational so could not prove cause and effect but said the rise in depression, loneliness and alcohol use and fall in exercise during Covid was “well known”.
“As such, there is a clear need to address these changes in lifestyle behaviour as a public health priority, and on the basis of the patterns of associations seen in the current study, we would hypothesise that interventions targeting these behaviours could benefit cognition.”
Prof Dag Aarsland, professor of old age psychiatry at King’s, said: “This study adds to the knowledge of the longstanding health consequences of Covid-19, in particular for vulnerable people such as older people with mild memory problems.”
Dr Dorina Cadar, a senior lecturer in cognitive epidemiology and dementia at Brighton and Sussex Medical School, who was not involved with the study, said it was clear the effects of the pandemic on the general population had been “catastrophic”.
“The new findings from the Protect study indicate domain-specific cognitive changes for individuals with a history of Covid-19 that mirrored similar trajectories for those with mild cognitive impairment but with a slightly lower rate of decline,” said Cadar in a linked comment in the Lancet Healthy Longevity journal.
“This study also highlights reduced exercise, alcohol use, depression, and loneliness as key risk factors that affected the rates of cognitive decline in the older population during the Covid-19 pandemic.”
