The outbreak of Coronavirus Disease 2019 (COVID-19) significantly affected our daily lives through measures such as stay-at-home requests, mask-wearing, and online classes. In this study, we analyzed longitudinal survey data collected from high school students in Tokyo, Japan, to investigate how their psychological states changed before and during the COVID-19 pandemic.
Researcher from the Research Center:
Masato S. Abe (Faculty of Culture and Information Science)
Research Background
Restrictions on social activities and school closures during the COVID-19 pandemic were widely believed to have had a substantial impact on adolescents’ mental health. Previous studies reported mixed findings: some suggested that psychological distress increased during the pandemic, while others found that temporary relief from academic and social pressures improved mental well-being.
However, many of these studies began after the onset of the pandemic and therefore could not directly compare psychological states before and during COVID-19. In addition, conventional psychological research often relies on simple total scores obtained by summing questionnaire responses, which may overlook the complex and dynamic nature of psychological states.
Research Overview
This study analyzed monthly responses to the Kessler Psychological Distress Scale (K6) collected from 84 high school students in Tokyo between July 2019 and September 2021. The survey period covered both the pre-pandemic and pandemic phases.
To analyze the data, we applied energy landscape analysis, a method originally developed in neuroscience and statistical physics. Rather than treating mental health as a single score, this approach represents psychological states as combinations of multiple questionnaire responses and visualizes the stability of those states and the likelihood of transitions between them over time.
For a subset of participants, brain MRI data were also analyzed to investigate the relationship between psychological-state dynamics and adolescent brain development.
Key Findings
By comparing data collected before and during the COVID-19 pandemic, we found that the overall group of high school students was less likely to experience psychological distress during the pandemic. Energy landscape analysis revealed that healthy psychological states became more stable, while transitions toward depressive states became less likely.
Furthermore, participants were classified into two groups based on the characteristics of their psychological-state dynamics. Students with more unstable psychological states showed greater developmental changes in parts of the frontal and temporal lobes of the brain.
These findings suggest that understanding mental health requires attention not only to questionnaire total scores but also to the temporal dynamics and stability of psychological states. The energy landscape analysis used in this study provides an intuitive way to visualize complex psychological processes and may offer a valuable new perspective for future mental health research and monitoring.
Publication Information
Tatematsu, D., Nakamura, N., Abe, M. S., Ishikawa, T., Ezaki, T., Cai, L., … & Iwami, S. (2026). Psychological distress among Japanese high school students during the COVID-19 pandemic: An energy landscape analysis. PLoS medicine, 23(1), e1004884.