The COVID-19 pandemic dramatically altered the lives of millions across the globe, but its impact may be more profound and lasting than we initially understood, especially for adolescents.
A new study from the University of Washington, recently published in the Proceedings of the National Academy of Sciences, reveals that the pandemic’s effects resulted in unusually accelerated brain aging in teenagers.
The research, which involved a comprehensive analysis of adolescent brain scans, suggests that the stress experienced during the pandemic may have led to premature brain aging, which could have far-reaching implications for young people’s mental and emotional development.
“We think of the COVID-19 pandemic as a health crisis,” Dr. Patricia Kuhl, co-author and co-director of the UW Institute for Learning & Brain Sciences, said in a press release. “But we know that it produced other profound changes in our lives, especially for teenagers.”
The study found that adolescents who lived through the pandemic showed brain changes akin to those typically seen in older individuals. These effects were notably more pronounced in girls, with a mean accelerated brain development rate of 4.2 years in females compared to 1.4 years in males.
The findings originated from a 2018 longitudinal study comparing brain scans of 160 youths between 9 and 17 years old. Researchers initially intended to evaluate the changes in brain structure during adolescence.
However, following the onset of the COVID-19 pandemic in early 2020, researchers realized they had a unique opportunity to explore the impact of pandemic lockdowns on adolescent brain development.
“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,” Dr. Neva Corrigan, lead author and research scientist at the University of Washington said. “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?”
Comparing the 2021 brain scans against the 2018 scans, researchers discovered that the brains of teenagers who experienced lockdowns and social restrictions appeared older than their pre-pandemic peers, reflecting an accelerated maturation process.
The human brain undergoes significant changes during adolescence, a period characterized by heightened neural plasticity and development. Regions such as the hippocampus, which plays a critical role in memory and emotional regulation, and the amygdala, which is essential for processing emotions, are particularly susceptible to environmental influences.
The study found that these regions in pandemic-era teens showed structural changes commonly associated with older age, such as a thinning of the cortex and increased volume in certain areas.
These changes are not inherently harmful and are part of normal brain maturation. However, when such changes occur too rapidly, they may disrupt the typical trajectory of brain development.
There were notable differences in accelerated brain aging based on gender. Male adolescents showed evidence of cortical thinning in two brain regions in the occipital lobe. Meanwhile, female scans showed “widespread” cortical thinning in 30 brain regions across both hemispheres and all brain lobes. The calculated rate of brain age acceleration was more than three times as significant in females (4.2 years) as in males (1.4 years).
Researchers called the sex differences in the patterns of accelerated brain aging “notable” while acknowledging that “the reasons for this marked sex difference in psychology and neurophysiology are unclear.”
One explanation for the significant sex difference in brain aging could be that females rely more heavily on peer relationships and emotional support than males.
“One very prominent lifestyle change associated with the COVID-19 pandemic was the dramatic decrease in interpersonal and peer-to-peer interactions,” researchers wrote. “The effect of the resulting isolation on the needs of male and female adolescents may have been very different, with females perhaps experiencing more stress than males associated with this prolonged isolation, resulting in a larger cascade of physiological effects.”
“What the pandemic really seems to have done is to isolate girls,” Dr. Kuhl added. “All teenagers got isolated, but girls suffered more. It affected their brains much more dramatically.”
The exact mechanisms behind these brain changes are equally uncertain. However, researchers believe that the unique stressors of the pandemic — including social isolation, family conflict, and uncertainty about the future — played a pivotal role.
During COVID lockdowns, adolescents were abruptly removed from their social environments, their daily routines were disrupted, and they faced new and profound uncertainties about their health, education, and social relationships.
The study aligns with previous research showing that chronic stress and exposure to trauma can accelerate aging in both the brain and body. However, the speed and extent of the observed changes make these findings particularly noteworthy.
“Teenagers really are walking a tightrope, trying to get their lives together,” Dr. Kuhl said. “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.”
The study’s authors caution that while these findings are significant, they do not necessarily mean that all adolescents will experience negative outcomes. However, the potential for long-term consequences is a serious concern.
Previous studies have shown that premature brain aging can be associated with a range of psychological disorders, including depression, anxiety, and substance abuse. Adolescents with prematurely aged brains may be at increased risk for developing these issues later in life, particularly if they lack adequate social support or mental health resources.
For example, a study published last year found that individuals who were college freshmen at the onset of the pandemic reported substantial increases in depression compared to pre-COVID levels. Similar to these recent findings, the increased rates of depression were more pronounced in females than males.
Ultimately, these findings underscore the importance of providing targeted support for adolescents navigating the post-pandemic landscape. Schools, families, and communities need to be aware of the potential for increased mental health needs among young people and take proactive steps to address them.
Organizations such as the American Academy of Pediatrics have already called for increased mental health screenings and services for young people in the wake of the pandemic. The study’s findings provide further evidence that such measures are essential, not just for immediate recovery but also for safeguarding the long-term health and development of a generation.
While the study provides crucial insights, it raises new questions about the long-term effects of accelerated brain maturation. Researchers stress the need for further studies to understand these full implications and identify which adolescents are most at risk.
“The findings of this study are also valuable for understanding the full impact of COVID-19 policy-mandated restrictions on adolescents,” researchers wrote. “Even prior to the pandemic, mental health was an unappreciated public health issue, and these findings add evidence for the necessity of new public health campaigns to provide support for adolescents and young adults struggling with mental health challenges, as the pandemic lockdowns dramatically increased the incidence of these types of disorders.”
“The pandemic provided a test case for the fragility of teenagers’ brains,” Dr. Kuhl added. “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.”
Tim McMillan is a retired law enforcement executive, investigative reporter and co-founder of The Debrief. His writing typically focuses on defense, national security, the Intelligence Community and topics related to psychology. You can follow Tim on Twitter: @LtTimMcMillan. Tim can be reached by email: tim@thedebrief.org or through encrypted email: LtTimMcMillan@protonmail.com