STANFORD, Calif. — Stress from the COVID-19 pandemic led to teenagers’ brains physically aging faster, new research reveals. Stanford University scientists report that pandemic-related stressors have literally altered the brain structure of adolescents, making them appear several years older in comparison to their peers prior to the global health crisis.
In 2020 alone, the study notes that reports of anxiety and depression among adults skyrocketed by over 25 percent. The new findings, published in the journal Biological Psychiatry, reveal that the neurological and mental health impact of COVID on teenagers may have been even worse.
“We already know from global research that the pandemic has adversely affected mental health in youth, but we didn’t know what, if anything, it was doing physically to their brains,” says first author Ian Gotlib, the David Starr Jordan Professor of Psychology in the School of Humanities & Sciences, in a media release.
How did the pandemic impact teen brains?
Gotlib explains that changes in brain structure occur naturally as people age. During puberty and early teenage years, adolescents experience increased growth in both the hippocampus and the amygdala. These are regions of the brain that control access to certain memories and help regulate emotions. At the same time, tissues in the cortex — the outer brain layer on top of the cerebrum which controls executive functioning — become thinner.
By comparing MRI scans from 163 children performed before and during the pandemic, Prof. Gotlib’s study discovered that this developmental process sped up among teenagers who experienced COVID-19 lockdowns.
Until now, accelerated changes in “brain age” have only appeared in children dealing with “chronic adversity” — such as violence or neglect. Prof. Gotlib says that although those experiences have a connection to poor mental health outcomes later in life, it’s still unclear if the changes in brain structure during the pandemic will have the same effect.
“It’s also not clear if the changes are permanent,” adds Gotlib, the director of the Stanford Neurodevelopment, Affect, and Psychopathology (SNAP) Laboratory.
“Will their chronological age eventually catch up to their ‘brain age’? If their brain remains permanently older than their chronological age, it’s unclear what the outcomes will be in the future. For a 70- or 80-year-old, you’d expect some cognitive and memory problems based on changes in the brain, but what does it mean for a 16-year-old if their brains are aging prematurely?”
The pandemic changed everything for scientists
Originally, the study was not looking for the impact of COVID stress on teen brain structure. Prior to the pandemic, Gotlib’s lab recruited a group of children and adolescents from the San Francisco Bay Area to participate in a long-term study on depression during puberty. However, when the pandemic began, researchers could not conduct their scheduled MRI scans on participants.
“Then, nine months later, we had a hard restart,” the study author explains.
By the time Gotlib could continue the brain scans, the study was a year behind schedule. Under normal circumstances, it’s possible to statistically correct for the delay while analyzing the brain scan data, but the pandemic was far from a normal event.
“That technique only works if you assume the brains of 16-year-olds today are the same as the brains of 16-year-olds before the pandemic with respect to cortical thickness and hippocampal and amygdala volume,” Gotlib continues.
“After looking at our data, we realized that they’re not. Compared to adolescents assessed before the pandemic, adolescents assessed after the pandemic shutdowns not only had more severe internalizing mental health problems, but also had reduced cortical thickness, larger hippocampal and amygdala volume, and more advanced brain age.”
An entire generation may have altered brain development
The professor says these findings could have “major implications” for other studies taking place during the pandemic. If youngsters who experienced the pandemic show accelerated brain development, scientists will have to account for that “abnormal” rate of growth in future research involving this unique generation.
“The pandemic is a global phenomenon – there’s no one who hasn’t experienced it,” Gotlib adds. “There’s no real control group.”
“Adolescence is already a period of rapid reorganization in the brain, and it’s already linked to increased rates of mental health problems, depression, and risk-taking behavior,” concludes co-author Jonas Miller, a former postdoctoral fellow in Gotlib’s lab who is now an assistant professor of psychological sciences at the University of Connecticut.
“Now you have this global event that’s happening, where everyone is experiencing some kind of adversity in the form of disruption to their daily routines – so it might be the case that the brains of kids who are 16 or 17 today are not comparable to those of their counterparts just a few years ago.”
South West News Service writer Stephen Beech contributed to this report.