2.2. Participants and Procedure
RECRUITMENT
The study participants were recruited between October 2022 and December 2022 from Gunma University in Gunma, Japan. The recruitment was made by posting posters at Gunma University. Study participation was also encouraged via e-mail and social networking services. Individuals aged ≥18 years who were native Japanese speakers and had a smartphone were considered eligible for this study. Participants who met the eligibility criteria were asked to complete the CES-D, GAD-7, and K6 scales (paper and smartphone versions) after answering demographic information (age and sex) and lifestyle characteristics (i.e., drinking, exercise, and smoking habits). The order in which the PROs were filled out (paper version first or smartphone version first) was randomly determined. To reduce potential recall and carryover effects, the interval between the completion of the two questionnaires was 1 week.