Covid was bad for our brains (even for those who didn't catch it)

Times

3 days ago

The Covid-19 pandemic was 'detrimental' to brain health, even for those who never contracted the virus, a study has suggested.
Academics say that the strain of the pandemic on people's lives may have aged our brains prematurely.
The team, from the University of Nottingham, found that brain ageing during the pandemic was 'more ­pronounced' among men, older people and those from deprived ­backgrounds.
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Dr Ali-Reza Mohammadi-Nejad, who led the study, said: 'What ­surprised me most was that even people who hadn't had Covid showed significant increases in brain ageing rates. It really shows how much the ­experience of the pandemic itself, everything from isolation to ­uncertainty, may have affected our brain health.'
The team trained a brain-ageing model on more than 15,000 healthy people, then applied the model to 1,000 people taking part in the UK Biobank study, a long-term piece of research tracking the health of British adults. Half of this group were assessed before the global pandemic, and half were assessed before and after.
The research, published in Nature Communications, found that those who had lived through the crisis had a '5.5 month higher deviation of brain age gap' compared with the people who were only assessed before the ­pandemic. 'We found that the Covid-19 pandemic was detrimental to brain health and induced accelerated brain ageing … regardless of Sars-CoV-2 ­infection,' the experts said.
The team also assessed cognitive ­performance by looking at tests taken at the time of the scans. Those infected with the virus were found to perform worse on cognitive tests when they were assessed before and after the pandemic.
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Professor Dorothee Auer, a senior author of the study, added: 'This study reminds us that brain health is shaped not only by illness, but by our everyday environment. The pandemic put a strain on people's lives, especially those already facing disadvantage. We can't yet test whether the changes we saw will reverse, but it's ­certainly possible, and that's an encouraging thought.'
Professor Masud Husain, from the University of Oxford and who is not ­affiliated with the research, urged 'caution' when interpreting the results. He said: 'The brain age difference between the two groups (as indexed by brain scanning) was on average only five months, and difference in cognitive performance between groups was only on the total time taken to complete one of the tests.
'Is this really going to make a significant difference in everyday life? The time between scans was much shorter in the people scanned before and after the pandemic, compared to those who had both scans before the pandemic. We therefore don't know if brain ageing would have recovered if more time elapsed.'
Previous research has found that people who had Covid performed less well in cognitive tests, especially executive function. Scientists from Imperial College London found that those who had had Covid scored about three IQ points lower than those who had not been ­infected. Those who had been in ­intensive care scored nine points lower, and those who suffer from long Covid scored about six points lower than uninfected individuals.