BETHESDA, Md. – The coronavirus pandemic has caused significant stress and uncertainty. This was especially true for young people who faced school closures, disrupted social channels and increased stress at home and in their communities. Given the unprecedented disruption caused by the pandemic, it is critical to understand its impact on health and development, particularly among adolescents.
New findings from a study funded by the National Institute of Mental Health shed light on how adolescents experiencing the COVID-19 pandemic and its accompanying shutdowns compare, both psychologically and biologically, to their pre-pandemic peers. Led by Stanford University’s Dr. Ian Gottlieb, the study is one of the first to examine the effects of the pandemic not only on adolescents’ mental health, but also on their brain structure, reflecting more lasting effects of adversity.
The sample consisted of 163 adolescents aged 13–17 years in San Francisco, California who participated in a larger longitudinal study. Half were assessed before the COVID-19 pandemic, and the other half were assessed after stay-at-home orders were issued in March 2020. There is neuroimaging data for 64 adolescents in each group. To narrow down the impact of the pandemic, the researchers matched the participants in the groups on other factors that could affect their mental health and brain development, including age, gender, puberty status, race and ethnicity, parental education, annual income of housekeeping and exposure to stress in early life.
Participants self-reported their symptoms of depression and anxiety and internalizing and externalizing mental health problems. MRI brain scans provide data on cortical thickness and volume in subcortical areas of the brain (amygdala, hippocampus, and nucleus accumbens). The researchers also fed the cortical and subcortical brain scans into a machine learning program developed by the ENIGMA-Brain Age working group to calculate the overall age of the participants’ brains.
The two groups differed significantly in both their mental health and brain development. Compared to the pre-pandemic group, adolescents assessed after the pandemic stopped reported more symptoms of anxiety and depression and greater internalizing problems. Their brains showed thinning of the cortex, which helps perform mental processes such as planning and self-control, and reduced volume in the hippocampus and amygdala, which are involved in accessing memories and regulating fear and stress responses, respectively.
Additionally, based on their cortical and subcortical characteristics, the post-suspension group had older brain ages than the adolescents assessed before the pandemic. Their brains showed neuroanatomical features more typical of older adults or those who experienced chronic stress or adversity in childhood. Thus, this study shows a link between the COVID-19 pandemic and impaired mental health and maladaptive brain development among adolescents.
Finally, the researchers consider the possibility that longer social distancing could exacerbate the psychobiological impacts of the pandemic. However, in analyzes examining changes in the post-suspension group based on the number of days since shelter-in-place orders began, no significant associations were observed with any of the measures of mental health or brain development.
In addition to replicating previous findings that the COVID-19 pandemic has adversely affected the mental health of adolescents, this study showed that the pandemic may have physically aged their brains. Compared with carefully selected peers assessed before the pandemic, adolescents who survived the pandemic-related shutdowns and went on to experience the ongoing disruption of COVID-19 had greater cortical thinning and larger hippocampal and amygdala volumes – neural changes that may reflect accelerated brain aging.
This study has important scientific and societal significance. First, researchers conducting longitudinal studies that span the pandemic will need to grapple with its possible impact on participants’ mental and physical health and be careful when making pre- and post-pandemic comparisons that assume normative development is unchanged. At the societal level, the results suggest that, at least in the short term, adolescents experience higher levels of depression and anxiety and may need mental health care to help them cope. Moreover, measurable changes in brain development suggest that they may also benefit from other services, such as those that support cognitive processes or emotion regulation.
Although the findings provide new information about the effects of the COVID-19 pandemic during a critical life stage, the authors emphasize that their findings need to be replicated and extended in more diverse samples. For example, the participants in the current study had relatively high socioeconomic status. However, marginalized groups, including people of low socioeconomic status, have been exposed to greater health, economic and psychological stress from the pandemic. Additionally, experiences surrounding stop orders—and the subsequent effects on mental health and brain development—reflect the policies of COVID-19 in a particular location in the United States.
Determining whether the results remain the same with more diverse groups and in different parts of the country will help inform public health policies aimed at reducing the adverse effects of the pandemic on health and development. The research team plans to assess these participants at age 20, and future studies should build on the current findings to determine the extent and sustainability of such change.