Internet Usage, Social Participation, and Depression Symptoms Among Middle-Aged and Older Adult Chinese Individuals Before and During the COVID-19 Pandemic: Evidence From the China Health and Retirement Longitudinal Observational Study

Siqian Zhang   ^{1, 2, 3 *} , MD ;   Shiju Dong   ^{1, 2, 3 *} , MD ;   Zexuan Yu   ⁴ , MD ;   Shuwen Bi   ^{1, 2, 3} , MD ;   Wen Wen   ^{1, 2, 3} , MD ;   Jiajia Li   ^{1, 2, 3} , PhD

¹ Department of Social Medicine and Health Management, Cheeloo College of Medicine, School of Public Health, Shandong University, Jinan, China

² NHC Key Lab of Health Economics and Policy Research, Shandong University, Jinan, China

³ Shandong Provincial Key New Think Tank, Center for Health Management and Policy Research, Shandong University, Jinan, China

⁴ The Dartmouth Institute for Health Policy and Clinical Practice, Dartmouth Hitchcock Medical Center, Geisel School of Medicine at Dartmouth, Lebanon, NH, United States

*these authors contributed equally