The COVID-19 lockdowns may have prematurely aged the brains of teenagers, particularly girls, according to a study conducted by researchers at the University of Washington. The study, published in the Proceedings of the National Academy of Sciences, found evidence of excessive and premature cortical thinning, a process that occurs with age and is accelerated by stress.
The research team began a longitudinal study in 2018, using magnetic resonance imaging (MRI) to document age-related structural changes in the brains of 160 teenagers aged between 9 and 17. The study was originally intended to track normal adolescent brain development, but the onset of the pandemic in 2020 presented an unexpected opportunity to examine the impact of the lockdowns on the teenage brain.
The researchers created a model based on the 2018 images to predict what the brain scans should have shown in 2021. They then compared these predictions with the actual images taken in 2021. The results showed that the first year of the pandemic aged teen brains by an average of 4.2 years for girls and 1.4 years for boys.
The study found that girls' brains showed significant thinning in areas associated with social cognition, suggesting that social isolation during the early months of the pandemic hit girls the hardest. "What the pandemic really seems to have done is to isolate girls. All teenagers got isolated, but girls suffered more. It affected their brains much more dramatically," said Patricia Kuhl, senior author of the study and co-director of the University of Washington's Institute for Learning & Brain Sciences, in a press release.
The cortical thinning, which is associated with depression and anxiety, is unlikely to correct or re-thicken. However, the researchers caution that while the study shows an association between the lockdowns and brain thinning, it does not definitively prove that the lockdown measures caused the thinning. Further research is needed to confirm whether lockdowns themselves were directly responsible for these effects.