Effects of COVID-19 pandemic on structural brain development in early adolescence

Abstract

The COVID-19 pandemic caused a global health crisis with large behavioral effects and serious stress and social consequences. Particularly, teenagers suffered pandemic-related social restrictions including school closures. This study examined whether and how structural brain development was influenced by the COVID-19 pandemic and whether pandemic length was associated with accumulating or resilience effects of brain development. We investigated structural changes in social brain regions (medial prefrontal cortex: mPFC; temporoparietal junction: TPJ) as well as the stress-related hippocampus and amygdala, using a longitudinal design of 2 MRI waves. We selected two age-matched subgroups (9–13 years old), one was tested before (n = 114) and the other during (peri-pandemic group, n = 204) the COVID-19 pandemic. Results indicated that teenagers in the peri-pandemic group showed accelerated development in the mPFC and hippocampus compared to the before-pandemic group. Furthermore, TPJ growth showed immediate effects followed by possibly subsequent recovery effects that returned to a typical developmental pattern. No effects were observed for the amygdala. The findings of this region-of-interest study suggest that experiencing the COVID-19 pandemic measures had accelerating effects on hippocampus and mPFC development but the TPJ showed resilience to negative effects. Follow-up MRI assessments are needed to test acceleration and recovery effects over longer periods.

Hippocampal Structures Among Japanese Adolescents Before and After the COVID-19 Pandemic

“…To our knowledge, only 2 recent studies have provided direct evidence that adolescents had a larger hippocampal volume during the COVID-19 pandemic than before it . Although the authors claimed that the COVID-19 pandemic accelerated adolescent brain maturation, they could not show the direct relationship between increased hippocampal volume and psychological conditions.…”

“…27,28 To our knowledge, only 2 recent studies have provided direct evidence that adolescents had a larger hippocampal volume during the COVID-19 pandemic than before it. 11,12 Although the authors claimed that the COVID-19 pandemic accelerated adolescent brain maturation, they could not show the direct relationship between increased hippocampal volume and psychological conditions. Given studies have shown that patients with PTSD who had been exposed to inherently stressful traumatic events always had a smaller hippocampal volume compared with healthy controls.…”

“…As the first months of the pandemic are believed to have the most significant impact on the developing brain, 12 we examined how the data collection time obtained through a logarithmic transformation was associated with hippocampal macrostructures and microstructures after the SoE. Accordingly, the primary hypothesis of the current study was that the SoE would cause an increase in the whole hippocampal volume during its development.…”

“…Only a few preliminary studies have suggested that compared with adolescents scanned before the COVID-19 pandemic, adolescents during the COVID-19 pandemic showed increased volume in the hippocampus, which may reflect accelerated brain maturation due to the COVID-19 pandemic. 11,12 However, extant studies still have some limitations, such as (1) the participants were measured only before and after the COVID-19 pandemic and were not tested in a prospective design according to adolescent development, (2) the participants were not recruited based on population representativeness, and (3) the studies only focused on the macrostructural alterations in the hippocampus, ignoring the alterations in hippocampal subfields and microstructure.…”