Scientists say COVID-19 lockdowns prematurely aged teen brains

By Stephen Beech via SWNS

COVID-19 lockdowns prematurely aged teenagers' brains by years - particularly for girls, reveals new research.

Restrictive rules imposed to try and stop the spread of the virus during the pandemic accelerated the brain development of teenage girls by an average of 4.2 years and 1.4 years in boys, according to the study.

Researchers believe girls suffered most because they felt particularly "isolated" from their friends during the pandemic.

The findings add to growing evidence that draconian lockdown measures - such as school closures - had a negative impact on the mental health of young people.

Scientists explained that adolescence is marked by dramatic changes in emotional, behavioral and social development.

It’s also a time when a sense of self-identity, self-confidence and self-control are developed.

However, the pandemic slashed social interactions for teenagers and led to anxiety, depression and stress - especially for girls.

The new research, published by the journal Proceedings of the National Academy of Sciences (PNAS), shows that the pandemic also resulted in "unusually accelerated" brain maturation in adolescents - with the effect more pronounced in teenage girls.

Senior author Professor Patricia Kuhl, of the University of Washington, said: “We think of the COVID-19 pandemic as a health crisis, but we know that it produced other profound changes in our lives - especially for teenagers."

She explained that brain maturation is measured by the thickness of the cerebral cortex, the outer layer of tissue in the brain.

The cerebral cortex naturally thins with age, even in teens.

But Kuhl said that chronic stress and adversity are known to accelerate cortical thinning, which is associated with an increased risk for the development of psychiatric and behavioral disorders.

Many of those disorders - such as anxiety and depression - often emerge during the teenage years, with females at a higher risk.

The research began in 2018 as a study of 160 youngsters aged between nine and 17, with the original objective of evaluating changes in brain structure during adolescence.

The participants were due to return in 2020, but the pandemic delayed the repeat tests until 2021.

By then, the researchers said that their original intent to study typical teen development was no longer viable.

Lead author Dr. Neva Corrigan said: “Once the pandemic was underway, we started to think about which brain measures would allow us to estimate what the pandemic lockdown had done to the brain.

“What did it mean for our teens to be at home rather than in their social groups - not at school, not playing sports, not hanging out?”

Using the original 2018 data, the Washington researchers created a model of expected cortical thinning during the teenage years.

The team then re-examined the brains of the adolescents, more than 80% of whom returned for the second set of measurements.

They found that the teenagers’ brains showed a general effect of accelerated thinning across adolescence, but it was "much more pronounced" in girls.

The researchers said that the cortical thinning effects in females were seen all over the brain, in all lobes and both hemispheres.

But, in boys, the effects were only seen in the visual cortex.

Kuhl believes the greater impact on female brains as opposed to male brains could be due to differences in the importance of social interaction for girls compared to boys.

She says that teenage girls often rely more heavily on relationships with other girls, prioritizing the ability to gather, talk to each other and share feelings, while boys tend to gather for physical activity.

Kuhl said: "Teenagers really are walking a tightrope, trying to get their lives together.

“They’re under tremendous pressure. Then a global pandemic strikes and their normal channels of stress release are gone.

"Those release outlets aren’t there anymore, but the social criticisms and pressures remain because of social media.

"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.”

Kuhl says the cerebral cortex is unlikely to get thicker again, but the potential for recovery might take the form of slower thinning over time, after the return of normal social interactions and outlets.

She says more research will be needed to see if that is the case.

Kuhl said: “It is possible that there might be some recovery.

“On the other hand, it’s also possible to imagine that brain maturation will remain accelerated in these teens.”

She added: “The pandemic provided a test case for the fragility of teenagers’ brains.

“Our research introduces a new set of questions about what it means to speed up the aging process in the brain.

"All the best research raises profound new questions, and I think that’s what we’ve done here.”