COVID lockdowns may have accelerated brain ageing in teenagers

A recent study by the University of Washington found that the COVID pandemic may have prematurely aged teenagers’ brains, particularly young girls.

Many people experienced disruptions to their daily lives and routines due to stay-at-home orders and limited social interactions during the COVID-19 pandemic, with this being shown to particularly affect the well-being of young people.
Now, a study by researchers at the University of Washington has found that the COVID-19 pandemic may have caused unusual changes in adolescents’ brain development, resulting in accelerated brain maturation.
“We were really surprised to find that in our post-COVID data the cortical thickness was a lot lower than it would be expected from the pre-COVID models, and we found this lower thickness was more pronounced and in a lot more regions in the brain in females than in males,” Neva Corrigan, lead author of the study and research scientist at the Institute for Learning & Brain Sciences at the University of Washington, told Euronews Health.
Initially, back in 2018, the researchers aimed to track normal brain changes in teenagers as part of a longitudinal study involving 160 participants aged nine to 17.
However, due to the pandemic, follow-up testing was delayed until 2021, prompting the researchers to shift their focus to how the pandemic might have affected brain development instead.
The researchers measured brain maturation by looking at how much the cerebral cortex, which is the outer layer of the brain, thinned over time.
The findings were published in the journal Proceedings of the National Academy of Sciences.
By comparing new scans with pre-pandemic data for 80 per cent of participants, they found that the adolescents’ brains thinned faster than expected, particularly for girls.
While this thinning naturally occurs with age, even in young people, girls’ brain development accelerated by an average of 4.2 years, while boys’ brains matured by 1.4 years.
“The cerebral cortex does thin as a normal process of ageing, and it does happen during adolescence, however, the thickness of the cerebral cortex in the post-COVID timeline was a lot lower than is normal for their age at those time points,” Corrigan said.
“That’s how we were able to determine that this was accelerated thinning that these kids are experiencing, which is basically accelerated ageing,” she added.
The study has several limitations, including a small sample size, lack of behavioural and lifestyle data, and limited understanding of how these factors or contracting COVID-19 may have influenced the results.
According to Corrigan, accelerated cortical thinning has been linked in past studies to severe trauma, stress and neglect in childhood, which led the researchers to hypothesise that these brain changes were due to the stress of the lockdowns.
Once thinned, the cerebral cortex is unlikely to thicken again, though the thinning might slow down once teenagers return to a normal social life, according to Patricia Kuhl, senior author of the study.
She added in a statement: “On the other hand, it’s also possible to imagine that brain maturation will remain accelerated in these teens”.
While Kuhl noted that more studies are still needed to assess the impact of cortex thinning in teenagers, previous research has linked accelerated cortical thinning to an increased risk of developing neuropsychiatric and behavioural disorders, such as depression, in adolescents.
“This is just another piece of evidence that lockdowns had consequences that weren’t anticipated by policymakers,” Corrigan said.
“We know that their academic performance suffered and kids are still suffering the consequences from that. We know that there has been an increased incidence in neuropsychiatric disorders, anxiety and depression, in people who experienced the pandemic, and I think it just points to the real importance of mental health support in our communities for young adults,” she continued.