The COVID-19 pandemic may have accelerated a decline in peoples’ brain health, particularly for older adults, even if they were never infected by the virus, new research finds.
The results of the study, which were published online in Nature Communications, showed that brain scans of adults who lived through the pandemic exhibited signs of faster brain aging than those who were scanned entirely before it. The most noticeable changes were in older adults, in men and in people from disadvantaged backgrounds.
“This study reminds us that brain health is shaped not only by illness, but by our everyday environment,” said Dorothee Auer, MD, PhD, a professor of neuroimaging at the University of Nottingham in England and senior author on the study, in a news release. “The pandemic put a strain on people’s lives, especially those already facing disadvantage.”
The researchers used longitudinal neuroimaging data from a UK Burbank study for their research. They looked at the brain scans of 996 healthy adults, some of which had brain scans before the pandemic and after the pandemic, and others only before it. Using advanced imaging and machine learning modeling, researchers developed an estimate of each person’s brain age, or how old their brain appeared compared to their actual age.
Their findings showed an average 5.5-month higher deviation of brain age gap (predicted brain age vs. chronological age) for the pandemic group compared with the control group.
“What surprised me most was that even people who hadn’t had COVID showed significant increases in brain aging rates,” said Ali-Reza Mohammadi-Nejad, PhD, who led the study. “It really shows how much the experience of the pandemic itself, everything from isolation to uncertainty, may have affected our brain health.”
The findings showed that only those participants who were infected by COVID-19 between their scans showed a drop in certain cognitive abilities such as mental flexibility and processing speed, which may suggest the pandemic’s brain aging effect for those who were not infected may be reversible. “We can’t yet test whether the changes we saw will reverse, but it’s certainly possible, and that’s an encouraging thought,” Auer said.