The brains of adolescents who were assessed after the pandemic shutdowns ended appeared several years older than those of teens who were assessed before the pandemic.
Until now, such accelerated changes in “brain age” have only been seen in children experiencing chronic adversity, such as neglect and family dysfunction.
A new study from Stanford University suggests that pandemic-related stressors have physically altered adolescents’ brains, making their brain structures appear several years older than the brains of comparable peers before the pandemic.
In 2020 alone, reports of anxiety and depression in adults rose by more than 25 percent compared to previous years.
Ian Gotlib, the Marjorie Mhoon Fair Professor of Psychology in the School of Humanities & Sciences, who is the first author on the paper, is also the director of the Stanford Neurodevelopment, Affect, and Psychopathology (SNAP) Laboratory at Stanford University.
Changes in brain structure occur naturally as we age, Ian Gotlib notes.
During puberty and early teenage years, kids’ bodies experience increased growth in both the hippocampus and the amygdala, areas of the brain that respectively control access to certain memories and help to modulate emotions.
At the same time, tissues in the cortex, an area involved in executive functioning, become thinner.
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.”
By comparing MRI scans from a cohort of 163 children taken before and during the pandemic, Gotlib’s study showed that this developmental process sped up in adolescents as they experienced the COVID-19 lockdowns.
Until now, he says, these sorts of accelerated changes in “brain age” have appeared only in children who have experienced chronic adversity, whether from violence, neglect, family dysfunction, or a combination of multiple factors.
Although those experiences are linked to poor mental health outcomes later in life, it’s unclear whether the changes in brain structure that the Stanford team observed are linked to changes in mental health, Gotlib noted.
“It’s also not clear if the changes are permanent,” said Gotlib, who is also the director of the Stanford Neurodevelopment, Affect, and Psychopathology (SNAP) Laboratory at Stanford University.
“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?”
Originally, Gotlib explained, his study was not designed to look at the impact of COVID-19 on brain structure.
Before the pandemic, his lab had recruited a cohort of children and adolescents from around the San Francisco Bay Area to participate in a long-term study on depression during puberty – but when the pandemic hit, he could not conduct regularly-scheduled MRI scans on those youth.
“Then, nine months later, we had a hard restart,” Gotlib said.
Once Gotlib could continue brain scans from his cohort, the study was a year behind schedule. Under normal circumstances, it would be possible to statistically correct for the delay while analyzing the study’s 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 said.
“After looking at our data, we realized that they’re not.”
These findings could have major implications for other longitudinal studies that have spanned the pandemic. If kids who experienced the pandemic show accelerated development in their brains, scientists will have to account for that abnormal rate of growth in any future research involving this generation.
For more information
Biological Psychiatry: Global Open Science
Effects of the COVID-19 Pandemic on Mental Health and Brain Maturation in Adolescents: Implications for Analyzing Longitudinal Data
Ian H. Gotlib, Jonas G. Miller, Lauren R. Borchers, Sache M. Coury, Lauren A. Costello, Jordan M. Garcia, Tiffany C. Ho.
CDC – Centers for Disease Control and Prevention
New CDC data illuminate youth mental health threats during the COVID-19 pandemic
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