It is already known that the pandemic has adversely affected mental health in youth globaly, but we didn’t know what, if anything, it was doing physically to their brains.
Changes in brain structure occur naturally as we age. During puberty and the 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 modulate emotions. At the same time, tissues in the cortex, an area involved in executive functioning, become thinner.
By comparing MRI scans from a cohort of 163 children taken before and during the pandemic, the study showed that this developmental process sped up in adolescents as they experienced the COVID-19 lockdowns.
Until now, these sorts of accelerated changes in the “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.
Mental and Psychological Effects of COVID-19
If their brain remains permanently older than their chronological age, it’s unclear what the outcomes will be in the future. This study was not designed to look at the impact of COVID-19 on brain structure.
Before the pandemic, the 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, they could not conduct regularly-scheduled MRI scans on those youth.
Compared to adolescents assessed before the pandemic, those assessed after the pandemic shutdowns not only had more severe internalizing mental health problems, but also had reduced cortical thickness, larger hippocampal and amygdala volumes, and a more advanced brain age.
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. These findings might also have serious consequences for an entire generation of adolescents later in life.
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.
In the future, researchers plan to continue following the same cohort of kids through later adolescence and young adulthood, tracking whether the COVID pandemic has changed the trajectory of their brain development over the long term.