**5. Conclusions**

The current study investigated the characteristics of depression between Chinese older adults during the COVID-19 pandemic. The study also examined the association between older adult's individual precautionary behaviors and their depression levels, and identified the role of SES indicators in moderating the behavior–depression relationship. All of the study hypotheses were supported. The depression levels of older adults differed significantly for marital status, living situations, education levels, household income, subjective health status, and infected cases of acquaintances. The inverse association between precautionary behavior change and depression levels was also identified in the current study. Of the three SES indicators, only household income significantly moderated the impacts of COVID-19 precautionary behaviors on older adults' depression levels. The research findings highlight the potential for embracing COVID-19 precautionary behaviors on mitigating depression levels among older adults. The findings also revealed the importance of considering socioeconomic disparities when promoting precautionary behaviors for mental health. These findings could be important in influencing relevant social policy decisions that target older adults.

**Author Contributions:** Y.D. and W.L. conceived and designed the study. Y.D., W.L., C.H., and J.H. contributed to the preparation of study materials. Y.D., W.L., Z.L., J.H., Y.W., and C.H. collected the data. W.L., B.S., and J.H. screened and analyzed the data. W.L. drafted the manuscript. Y.D., J.S.B., and B.S. revised and polished the manuscript. Y.D. and W.L. had full access to all study data and take responsibility for the integrity of the data and the accuracy of the data analysis. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was supported by the Start-Up Grant and Strategic Development Fund (SDF) of Hong Kong Baptist University. The funding organization had no role in the study design, study implementation, data collection, data analysis, manuscript preparation, or publication decision. The work is the responsibility of the authors.

**Institutional Review Board Statement:** Ethical approval for conducting the study was obtained from the Research Ethics Committee of Hong Kong Baptist University (REC/19-20/0490).

**Informed Consent Statement:** Informed consent was obtained from all subjects involved in the study.

**Conflicts of Interest:** The authors declare no conflict of interest.
