Reports of anxiety and depression in adults increased by more than 25% in 2020 compared to previous years. Recently published findings suggest that the pandemic’s neurological and mental health effects on adolescents may have been even worse.
According to the research, pandemic-related stressors physically altered teenagers’ brains, making their brain structures appear several years older than those of comparable peers prior to the pandemic.
“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,”
first author Ian Gotlib, professor of psychology at Stanford University, said.
Accelerated Brain Age
Natural changes in brain structure occur as we age. During puberty and early adolescence, children’s bodies experience increased growth in the hippocampus and the amygdala, two areas of the brain that control access to specific memories and help to modulate emotions. Tissues in the cortex, a region important for executive function, thin at the same time.
Comparing MRI scans of 163 children taken before and during the pandemic, Gotlib’s study revealed that this developmental process accelerated in adolescents during the COVID-19 lockdowns.
Until now, he said, these kinds of fast changes in “brain age” have only been seen in children who have been through long-term hardships, such as neglect, violence, family problems, or a mix of these and other things.
Mental Health Impacts Unknown
Gotlib notes that although these experiences are associated with poor mental health outcomes later in life, it is unclear whether the changes in brain structure observed by the team are related to changes in mental health.
“It’s also not clear if the changes are permanent. 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,”
said Gotlib, director of the Stanford Neurodevelopment, Affect, and Psychopathology (SNAP) Laboratory at Stanford University.
Based on brain changes, you would anticipate cognitive and memory issues in a 70- or 80-year-old, but what does it mean for a 16-year-old whose brains are prematurely aging?
Depression During Puberty
The original purpose of Gotlib’s study was not to examine the effect of COVID-19 on brain structure.
Prior to the pandemic, his lab had recruited a cohort of children and adolescents from the San Francisco Bay Area to participate in a long-term study on depression during puberty; however, he was unable to conduct regularly-scheduled MRI scans on them due to the pandemic.
“Then, nine months later, we had a hard restart,”
Gotlib said.
Once Gotlib was able to continue brain scans on his cohort, the study fell behind schedule by one year. In a normal situation, the delay would be easy to account for statistically when looking at the study’s data. However, the pandemic was anything but normal.
“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 explained.
Upon examining the data, they concluded that they are 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 thinner cortical layers, larger hippocampal and amygdala volumes, and older brains.
Long-term Consequences
These findings may have significant ramifications for other longitudinal studies that span the pandemic. If children who experienced the pandemic exhibit accelerated brain development, scientists will have to account for this abnormal growth rate in future studies involving this generation.
As Gotlib points out, the pandemic is a global phenomenon. There’s no one who hasn’t experienced it. There’s no real control group.
Jonas Miller, who was a postdoctoral fellow in Gotlib’s lab at the time of the study and is now an assistant professor of psychological sciences at the University of Connecticut, says that these results may also have long-term effects on a whole generation of teenagers.
“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. 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,”
said Miller.
Gotlib plans to continue tracking the same cohort of children through late adolescence and young adulthood to determine whether the COVID pandemic has altered the long-term trajectory of their brain development. He also plans to keep an eye on the teens’ mental health and compare the brain structures of those who were infected with the virus to those who were not, to see if there are any small differences.
Reference: Ian H.Gotlib, Jonas G. Miller, et al. Effects of the COVID-19 Pandemic on Mental Health and Brain Maturation in Adolescents: Implications for Analyzing Longitudinal Data. Biological Psychiatry Global Open Science, 2022, ISSN 2667-1743