During the COVID-19 pandemic, governments around the world implemented restrictive measures, such as stay-at-home orders and school closures, to mitigate the spread of the respiratory disease. It is well documented that this disruption of daily routines and social activities had a negative impact on adolescents’ mental health.
Adolescence, the transition period between childhood and adulthood, is marked by dramatic changes in emotional, behavioral, and social development. It is also a time when you develop a sense of self-identity, self-confidence and self-control. The pandemic reduced social interaction among adolescents and led to documented reports of anxiety, depression and stress, especially for girls.
New research from the University of Washington, published online September 9 in the Proceedings of the National Academy of Sciencesfound that the pandemic also caused unusually accelerated brain maturation in adolescents. This maturation was more pronounced in girls. When measured in terms of the number of years of accelerated brain development, the mean acceleration was 4.2 years in women and 1.4 years in men.
“We view the COVID-19 pandemic as a health crisis,” said Patricia Kuhl, lead author and co-director of the UW Institute for Learning and Technology. Brain Sciences (I-LABS), “but we know that it produced other profound changes in our lives, especially in adolescents.”
Brain maturation is measured by the thickness of the cerebral cortex, the outer layer of brain tissue. The cerebral cortex naturally thins with age, even in adolescents. Chronic stress and adversity are known to accelerate cortical thinning, which is associated with an increased risk of developing neuropsychiatric and behavioral disorders. Many of these disorders, such as anxiety and depression, typically emerge during adolescence, and women are at higher risk.
The UW research began in 2018 as a longitudinal study of 160 adolescents ages 9 to 17, with the original goal of assessing changes in brain structure during typical adolescence. The cohort was scheduled to return in 2020, but the pandemic delayed repeat testing until 2021. By then, the original intention to study typical adolescent development was no longer feasible.
“Once the pandemic was underway, we started thinking about what brain measurements would allow us to estimate what the pandemic lockdown had done to the brain,” said Neva Corrigan, lead author and research scientist at I-LABS. “What did it mean for our teenagers to be at home instead of in their social groups, not going to school, not playing sports, not hanging out?” Using the original data from 2018, the researchers created a model of expected cortical thinning during adolescence. They then re-examined the teens’ brains, more than 80% of whom returned for the second set of measurements. The adolescents’ brains showed an overall effect of accelerated cortical thinning throughout adolescence, but this was much more pronounced in women.
The effects of cortical thinning in women were observed throughout the brain, in all lobes and in both hemispheres. In men, the effects were only seen in the visual cortex. The greater impact on female brains compared to males could be due to differences in the importance of social interaction for girls versus boys, Kuhl said. She added that teenage girls often rely more on relationships with other girls, prioritizing the ability to come together, talk to each other and share feelings. Kids tend to get together to do physical activity.
“Teenagers are really walking a tightrope, trying to get their lives together,” Kuhl said. “They are under tremendous pressure. Then a global pandemic hits and their normal stress release channels disappear. Those release outlets are no longer there, but the social criticism and pressures remain because of social media. What there really seems to be “The pandemic is actually isolating the girls. All the teenagers isolated themselves, but the girls suffered more. It affected their brains much more dramatically.”
The cerebral cortex is unlikely to get thicker again, Kuhl said, but the potential for recovery could take the form of slower thinning over time, after the return of normal social interactions and outings. More research will be needed to see if this is the case.
“There may be some recovery,” Kuhl suggested. “On the other hand, it is also possible to imagine that brain maturation will continue to accelerate in these adolescents.” In older populations, measures of cognitive brain function, such as processing speed and the ability to complete typical tasks, correlate with thinning of the cerebral cortex. That kind of data isn’t yet available for teens, Kuhl said, but it could be where future research is headed.
“The pandemic provided a test case for the fragility of adolescent brains,” Kuhl concluded. “Our research introduces a new set of questions about what it means to accelerate the aging process in the brain. All the best research raises profound new questions, and I think that’s what we’ve done here,” added Ariel Rokem, co-author and professor. UW Psychology Research Associate and Data Science Fellow at the eScience Institute.
For Ignacio Morgado, professor of Psychobiology at the Institute of Neurosciences of the Autonomous University of Barcelona, ”The study and its results are of special interest, not only because they reveal a process of acceleration of brain maturation due to COVID, especially in girls, where this process is normally already more accelerated than in boys, but because it opens the door to consider and investigate possible environmental factors, including disease processes, that could modify the speed of brain maturation in adolescents,” according to stated in statements to Science Media Center Spain.
Source: University of Washington
