Adolescent girls who lived through Covid-19 lockdowns experienced faster brain aging than boys, according to data suggesting the social restrictions had a disproportionate impact on them.
MRI scans found evidence of premature brain aging in both boys and girls, but girls’ brains appeared an average of 4.2 years older than expected after lockdown, compared with 1.4 years older for boys.
It is unclear whether the changes have negative consequences, but the findings have raised concerns that they could affect adolescents’ mental health and potential to learn.
“We were shocked by this data, that the difference is so dramatic,” said Prof Patricia Kuhl, associate director of the Institute for Learning and Brain Sciences at the University of Washington, in Seattle.
The researchers collected MRI scans from 160 nine- to 17-year-olds in 2018 and used them to build a model of how the brain’s cortex normally thins during school years. Some cortical thinning is natural and an important part of brain maturation and specialization in adolescence.
The team revisited the same group in 2021 and 2022, after lockdowns, and collected further MRI scans from those aged 12 to 16. Compared to pre-pandemic brain development, it showed signs of accelerated cortical thinning in one area of the boys’ brains, and in 30 of the girls’ brains, across both hemispheres and all lobes.
Other researchers have linked premature brain aging to the pandemic, but the latest study, in Proceedings of the National Academy of Sciencesis the first to reveal sharp differences between boys and girls.
Both sexes showed signs of accelerated aging in a brain region linked to vision, which may affect the processing of faces. But in women, brain changes were widespread. Many affected areas that underlie social cognition with roles in processing emotions, interpreting facial expressions and understanding language, which the researchers say are critical for communication.
Kuhl believes the difference reflects girls’ greater reliance on social groups and interactions. “Girls chat endlessly and share their emotions,” she said. “They are much more dependent [than boys] on the social scene for their well-being and for their healthy neural, physical and emotional development.”
More studies are needed to see if brain aging affects cognitive performance, but Kuhl notes that premature cortical thinning is linked to early life adversity and a greater risk of neuropsychiatric disorders. Cortical thinning is essential for the brain to specialize, but it comes with a loss of cognitive flexibility that can potentially affect learning.
Kuhl said the findings were a “reminder of the fragility of teenagers” and suggested that parents talk to their teens about their experiences of the pandemic. “It is important that they invite their teenagers for a coffee, for a tea, for a walk, to open the door for conversation,” she said. “Whatever it takes to open them.”
“It is important to recognize that although the pandemic is largely over, the effects of the stress of the pandemic are still there for children and adolescents,” said Ian Gotlib, a professor of psychology at Stanford University who reported similar brain changes. “Making sure that youth are supported in terms of their mental health is critical, perhaps now more than ever.”
“This adds to our understanding that adolescents experienced accelerated brain changes as a result of the Covid-19 pandemic,” said Dr Lina van Drunen, a researcher at Leiden University in the Netherlands, who reported. similar brain changes in adolescents. Identifying the specific factors behind premature aging and understanding its long-term impact was now key, she added.
