*2.1. Patient and Public Involvement*

Data were collected as part of the research project, "Basic research for exploring the ideal medical intervention after the advent of the new coronavirus", of the Research Institute of Economy, Trade, and Industry (RIETI). The online survey was called, "the 2020 Continuing survey on mental and physical health during the COVID-19 pandemic" (hereinafter RIETI questionnaire survey), and NTTCom Online Marketing Solutions Corporation was commissioned to conduct it. The data used in our study were microdata of the first survey conducted during the period 27 October–6 November 2020. The content of the questions is presented in Supplementary Table S1.
