Generational Digital Divide of Health Communication: Social Media Use Motivations, Perceived Social Support, and Mental Health in China.

Despite a growing body of research that has examined the correlation between social media usage and mental health, two limitations remain: the lack of generational comparative studies and the oversimplification of social media use measurements in previous research, which often focused on frequency, duration, and active/passive usage. Drawing on two cross-sectional Chinese datasets (Study 1: N = 30,054; Study 2: N = 603), this study investigated the generational differences in "social media use → perceived social support → mental health" from a motivation perspective. Study 1 found that older adults reported lower levels of social media use motivations, while younger and middle-aged individuals showed higher engagement. For young adults, each social media use motivation was positively related to perceived social support, which in turn was linked to better mental health. Among middle-aged adults, the same pattern held for four motivations, but seeking self-status did not show a positive association with perceived social support. In contrast, among older adults, all media motivations, except for relaxation, were associated with perceived social support and mental health outcomes negatively, highlighting a generational digital divide. Study 2 replicated some findings of Study 1 and found that emotional social support - rather than informational support - could significantly mediate the relationship between information-seeking motivation and mental health. These findings underscore the need for tailored health communication strategies and interventions that account for generational differences and help bridge the digital divide.