New studies indicate that the lockdowns enforced during the COVID-19 pandemic led to a noticeable increase in the pace of brain development among adolescents, specifically more significant in females.
As a response to the COVID-19 pandemic, numerous governments worldwide enacted strict measures, including stay-at-home mandates and the closure of schools, to curb the spread of the virus. It’s widely recognized that these changes disrupted daily life and social interactions, leading to adverse effects on the mental well-being of teenagers.
Adolescence is the stage of life when individuals transition from childhood to adulthood, characterized by significant emotional, social, and behavioral growth. This phase is crucial for developing self-identity, self-esteem, and self-regulation. Due to the pandemic, teenagers experienced reduced social contact, which resulted in increased reports of anxiety, depression, and stress, particularly among girls.
Recent findings from the University of Washington, shared online on September 9 in the Proceedings of the National Academy of Sciences, revealed that the pandemic resulted in a quicker rate of brain development in adolescents. Notably, this effect was more marked in females, showing an average acceleration of 4.2 years in brain maturation for girls and 1.4 years for boys.
“While the COVID-19 pandemic is often viewed as a health crisis,” stated Patricia Kuhl, senior author and co-director of the UW Institute for Learning & Brain Sciences (I-LABS), “it also caused significant changes in our lives, especially impacting teenagers.”
Brain development can be assessed by examining the thickness of the cerebral cortex, the brain’s outer layer. Typically, the cerebral cortex becomes thinner as individuals age, a process that begins during the teenage years. Chronic stress and challenging experiences can hasten this thinning process, which is linked to a higher likelihood of developing neuropsychiatric and behavioral issues. Many of these conditions, including anxiety and depression, frequently arise during adolescence, with girls facing a greater risk.
This research initiative kicked off in 2018 as a longitudinal study involving 160 teens aged 9 to 17, initially aiming to track changes in brain structure throughout typical adolescent development.
The participants were expected to return for further assessments in 2020, but the pandemic delayed these tests until 2021, making it impossible to achieve the original goal of studying standard teen growth.
“Once the pandemic struck, we began to consider which metrics would reveal what impact the lockdown had on the adolescents’ brains,” explained Neva Corrigan, lead author and research scientist at I-LABS. “We questioned how staying home instead of engaging with peers—like going to school, playing sports, or socializing—affected our teens.”
Utilizing the initial 2018 data, researchers developed a model to predict the expected cortical thinning during adolescence. They then re-evaluated the brains of the adolescents, more than 80% of whom returned for follow-up measurements. The results indicated a general pattern of accelerated thinning in the adolescents’ brains, which was significantly more evident in females. In contrast to females, males only displayed these thinning effects in the visual cortex.
The heightened impact observed in female brains compared to males may stem from the stronger reliance girls have on social interactions. Kuhl noted that teenage girls typically prioritize relationships with their peers, valuing time spent together for conversation and emotional sharing, while boys tend to engage more in physical activities.
“Teenagers are navigating a challenging phase of life,” Kuhl said. “They face immense pressure. When a global pandemic hits, their usual ways to cope with stress vanish. Those outlets are no longer accessible, yet social media continues to present pressures and criticisms. The pandemic has seemingly isolated girls, who endured significantly more adverse effects on their mental state and brain development than boys.”
Kuhl mentioned that while the cerebral cortex is unlikely to regain thickness, there could be potential for a slower thinning process over time as normal social activities resume. Further studies are necessary to determine if this recovery is feasible.
“Recovery may be possible,” Kuhl stated. “Conversely, it’s also conceivable that brain maturation could consistently remain accelerated for these teens.”
In older populations, metrics of cognitive brain functions, like processing speed and task completion ability, are often linked with the degree of cortical thinning. Currently, such data for teenagers is unavailable, but Kuhl suggested that this could become a focal point for future studies.
“The pandemic offered a unique opportunity to examine the vulnerabilities of teenage brains,” Kuhl commented. “Our research raises a fresh set of questions about the implications of hastening brain aging. The most valuable research prompts significant questions, and this is precisely what we have achieved.”
Ariel Rokem, a UW research associate professor of psychology and data science fellow at the eScience Institute, is an additional co-author. The study received funding from a grant provided by the Bezos Family Foundation.
