BETHESDA, Md. — The coronavirus pandemic caused significant stress and uncertainty. This was particularly true for young people, who faced school shutdowns, severed social channels, and amplified stress at home and in their communities. Given the unprecedented disruption caused by the pandemic, it is crucial to understand its impact on health and development, especially among adolescents.
New findings from a study funded by the National Institute of Mental Health shed light on how adolescents living through the COVID-19 pandemic and its accompanying shutdowns compare, both psychologically and biologically, to their peers before the pandemic. Led by Ian Gotlib, Ph.D., at Stanford University, 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 were participating in a larger longitudinal study. Half were assessed before the COVID-19 pandemic, and the other half were assessed after stay-at-home shutdown orders were issued in March 2020. Neuroimaging data were available for 64 adolescents in each group. To narrow in on the impact of the pandemic, the researchers matched participants in the groups on other factors that might affect their mental health and brain development, including age, sex, pubertal status, race and ethnicity, parental education, annual household income, and exposure to early life stress.
Participants self-reported their depression and anxiety symptoms and internalizing and externalizing mental health problems. MRI brain scans provided data on cortical thickness and volume in subcortical brain areas (amygdala, hippocampus, and nucleus accumbens). The researchers also entered the cortical and subcortical brain scans into a machine-learning program developed by the ENIGMA-Brain Age working group to calculate participants’ overall brain age.
The two groups differed significantly in both their mental health and brain development. Compared to the pre-pandemic group, adolescents assessed after the pandemic shutdowns reported more symptoms of anxiety and depression and greater internalizing problems. Their brains showed thinning of the cortex, which helps execute mental processes like planning and self-control, and reduced volume in the hippocampus and amygdala, which are involved in accessing memories and regulating responses to fear and stress, respectively.
Moreover, based on their cortical and subcortical features, the post-shutdown group had older brain ages than adolescents assessed before the pandemic. Their brains showed neuroanatomical features more typical of older people or those who experienced chronic stress or adversity in childhood. Thus, this study shows an association between the COVID-19 pandemic and impaired mental health and maladaptive brain development among adolescents.
Last, the researchers considered the possibility that a longer duration of social distancing exacerbated the psychobiological impacts of the pandemic. However, in analyses examining changes in the post-shutdown group based on the number of days from the start of the shelter-in-place orders, no significant associations were observed with any of the mental health or brain development measures.
In addition to replicating prior findings that the COVID-19 pandemic adversely affected adolescents’ mental health, this study showed that the pandemic may have physically aged their brains. Compared to carefully matched peers assessed before the pandemic, adolescents who lived through the pandemic-related shutdowns and continued to experience COVID-19’s ongoing disruptions had greater cortical thinning and larger hippocampal and amygdala volumes—neural alterations that may reflect accelerated brain aging.
This study has important scientific and societal implications. First, researchers conducting longitudinal studies that span the pandemic will have to contend with its possible impact on participants’ mental and physical health and be careful when making pre- to post-pandemic comparisons that assume normative development is unchanged. On a societal level, the results suggest that, at least in the short term, adolescents are experiencing greater 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 supporting cognitive processes or emotion regulation.
Although the findings provide novel information about effects of the COVID-19 pandemic during a critical life stage, the authors emphasize that their findings should be replicated and extended in more diverse samples. For instance, participants in the current study had a relatively high socioeconomic status. However, marginalized groups, including people with low socioeconomic status, have been exposed to greater health, economic, and psychological stresses from the pandemic. In addition, experiences around the shutdown orders—and subsequent effects on mental health and brain development—reflected COVID-19 policies in a specific 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 persistence of such change
