Only participants who were infected with COVID-19 between their scans showed a drop in certain cognitive abilities, such as mental flexibility and processing speed.

What else did the study find?

“Even people who hadn’t had COVID-19 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,” he said.

“The pandemic put a strain on people’s lives … we can’t yet test whether the changes we saw will reverse, but it’s certainly possible, and that’s an encouraging thought,” she said.

What shapes brain health — and why it matters?

Dr Oscar Murphy, a senior clinical research fellow at Australian medical research group the Bionics Institute, explained how our brain health can change.

As we age, our brain’s ability to communicate slowly gets worse, which can be accelerated by external factors like stress and anxiety.