The study was conducted by researchers from the Department of Psychology, Stanford University-USA.
The ongoing COVID-19 pandemic has caused significant stress and disruption for young individuals, likely leading to alterations in their mental health and neurodevelopment.
The study findings were published in the peer reviewed Journal: Global Open Science.
In addition to replicating prior findings that the pandemic has adversely affected the mental health of young people (5), we found that adolescents assessed during the pandemic have neuroanatomical features that are more typical of individuals who are older or who experienced significant adversity in childhood.
Compared to carefully matched peers assessed before the pandemic, adolescents assessed during the pandemic showed signs of advanced cortical thinning and had larger bilateral hippocampal and amygdala volumes.
Given that volume in these structures typically increases over adolescence (33), these neural alterations may reflect accelerated brain maturation in the context of the pandemic. Indeed, adolescents assessed during the pandemic also had larger positive brain age gap estimates, indicative of older-appearing brains.
It appears, therefore, that the pandemic not only has adversely affected adolescents’ mental health, but also has accelerated their brain maturation.
These findings have critical implications for researchers who are conducting longitudinal studies that were interrupted due to pandemic-related shutdowns. In our own longitudinal study, we had been assessing a sample of approximately 200 adolescents at each of four timepoints, at two-year intervals, to examine the effects of early adversity on trajectories of neurodevelopment and clinical symptoms.
At the time of the shutdown, we were two-thirds of the way through the third assessment, when our participants were 13-17 years of age. We had originally planned to simply use participants’ age in analyzing trajectories from our four timepoints of data. Although some participants would have had a longer interval than others between assessments that bracketed the shut-down, we would control statistically for those differences.
It is important to recognize that this analytic approach assumes that, for example, 16-year-olds who were assessed after the shutdown ended are equivalent in their clinical functioning and neurodevelopment to 16-year-olds who were assessed before the pandemic, and would simply be grouped together.
Our results suggest that this assumption is not correct. Rather, the pandemic appears to have altered adolescent mental health and neurodevelopment, at least in the short term, which will present a challenge for researchers in analyzing longitudinal data from studies of normative development that were interrupted by the pandemic.
In order to not confound age-related changes in brain maturation with experiences and consequences of the COVID-19 pandemic, some researchers, including our group, have used a dummy-coded variable to control statistically for whether participants were assessed pre- or during the pandemic (e.g., 34).
Nevertheless, restrictions around COVID-19 are constantly changing; therefore, additional measures may need to be used as covariates, including the interval between shelter-in-place orders and time of assessment, as well as the nature and severity of the individual’s stress and experience during the pandemic (e.g., COVID-19 infection, upheaval in living situation, financial strain, etc.).
We should note that our sample is of relatively high socioeconomic status and represents the racial/ethnic composition of the San Francisco Bay Area. Researchers have reported that sample composition influences age-related effects on brain structure (35) and, more specifically, that the psychosocial and health consequences of the pandemic have been more severe among individuals from socially marginalized groups (e.g., lower socioeconomic status; 36–38).
Therefore, it is important that investigators examine the effects of the COVID-19 pandemic on psychopathology and brain metrics in more diverse samples of adolescents that are representative of the broader population.
Another critical task for future research is to determine whether these alterations are temporary effects of the pandemic or stable changes that will characterize the current generation of youth. If these changes are found to be enduring, accounting for and interpreting data acquired during this period will require additional attention and consideration.
For example, as more researchers publish data concerning normative developmental trajectories of MRI-derived anatomical features (e.g., 39), it will be possible to compare COVID-impacted neurodevelopmental trajectories with normative trajectories and, indeed, to compute COVID-adjusted metrics of brain maturation.
Regardless, however, we emphasize that it is important that we continue to follow and assess individuals who were recruited and assessed prior to the pandemic; this type of research offers the strongest possibility for us to examine the effects of a major stressor experienced on a global scale.