A recent study conducted by the University of Washington has revealed that COVID-19 lockdowns, including school closures, canceled sports, and stay-at-home orders, accelerated brain aging in teenagers by up to four years. The study, published in the Proceedings of the National Academy of Sciences, highlights how the disruptions to daily routines may have contributed to behavioral issues, eating disorders, and heightened anxiety and depression in adolescents.
Impact on adolescent brain development
Researchers from the university’s Institute for Learning & Brain Sciences (I-LABS) began tracking the brain structure of 160 teens in 2018 through MRI scans. The participants, who were evenly split between boys and girls, were between 9 and 19 years old at the start of the study.
When the Covid lockdowns began in 2020, the research team, led by Patricia Kuhl, co-director of I-LABS, had to pause the brain scans until 2021. This delay shifted the focus of the research to examine how the lockdowns may have impacted the structural development of adolescent brains.
“We discovered that the brains of teenage boys had aged by 1.4 years, while the brains of girls showed accelerated aging by as much as 4.2 years,” Kuhl stated.
Brain aging: The role of the cerebral cortex
The study measured the thickness of the cerebral cortex, the brain’s outer layer responsible for reasoning, decision-making, and other higher-level functions. The cerebral cortex naturally thins with age and is also affected by chronic stress.
“In just three years, we observed much more thinning in the brain than we had anticipated,” said Kuhl. “As we age, the thinning of the cortex is associated with slower processing times and less flexible thinking. All the teens in our study showed this accelerated aging.”
The impact was especially pronounced in teenage girls, where the thinning occurred across 30 regions of the brain, spanning both hemispheres and all lobes. In boys, the thinning was restricted to just two regions in the occipital lobe, which is crucial for visual processing.
Social factors contributing to gender differences
Kuhl suggested that social interactions may play a role in why the effects were more pronounced in girls. While boys tend to engage in group sports or physical activities, girls often rely on personal relationships for emotional support.
“When girls and women are stressed, there’s a natural response to seek emotional connection, which releases neurotransmitters like oxytocin,” explained Dr. Ellen Rome, head of adolescent medicine at Cleveland Clinic Children’s Hospital, who was not involved in the study.
Long-term risks of ‘pandemic brains’
While the study does not definitively prove that lockdowns caused changes in brain structure, it does suggest a correlation between cortical thinning and increased rates of anxiety, depression, and behavioral issues in teens. Mental health disorders among children were already rising before COVID-19, but the pandemic exacerbated the issue.
Another study from Stanford University in 2022 observed similar changes in the brains of teens during the pandemic. Researchers compared the stress and disruptions of COVID-19 to childhood traumas like violence and family dysfunction.
“The pandemic was traumatic for everyone, but for young people experiencing critical emotional and behavioral development, the isolation had a more profound impact,” said Kuhl.
Widespread mental health implications
Reports from the Centers for Disease Control and Prevention (CDC) since 2021 have highlighted unprecedented levels of hopelessness and suicidal thoughts among teenagers. Although a CDC survey in August 2023 indicated a slight improvement, 53% of high school girls still reported persistent feelings of sadness.
“The teenage years are a vital period for social development,” noted Dr. Jonathan Posner, professor of psychiatry at Duke University School of Medicine. “Without those social interactions, there’s a loss of key social learning opportunities.”
Can ‘pandemic brains’ recover?
It remains unclear whether the accelerated aging of young brains during the pandemic could increase the risk of future disorders such as ADHD, depression, or even diseases like Alzheimer’s or Parkinson’s. According to Kuhl, the cortex cannot regrow and continues to thin throughout life.