Social media use and depression among middle-aged and older Chinese adults: mediating roles of health literacy and perceived social support

Background Most research on social media use and depression has focused on young adults. A few studies in middle-aged and older Chinese adults have reported a negative association, but the underlying mechanisms remain unclear. Methods A cross-sectional survey was conducted among middle-aged and older adults ( n = 2,743) in five cities of Hainan Province, China. Participants completed the Patient Health Questionnaire-9, the Social Media Use Integration Scale, the Short-Form Health Literacy Questionnaire, and the Perceived Social Support Scale. Mediation and moderation models were tested using the PROCESS macro with bootstrap methods. Results Social media use was significantly negatively associated with depression ( B = −0.045, p < 0.001). Health literacy ( B = −0.009, 95% CI [−0.013, −0.005]) and perceived social support ( B = −0.015, 95% CI [−0.019, −0.011]) mediated this relationship. Education level strengthened the positive associations of social media use with health literacy ( B = 0.003, p < 0.05) and perceived social support ( B = 0.019, p < 0.001). Conclusion Social media use was associated with lower levels of depression among middle-aged and older adults. Health literacy and perceived social support may serve as potential pathways underlying this association. In addition, these associations varied by education level.