Beyond the individual: A dyadic longitudinal study of internet use, social participation, and depressive symptoms in older couples.

Background: While the link between internet use and depressive symptoms in older adults is studied, research often overlooks the interdependent nature of couples. This study examines the longitudinal actor and partner effects of internet use on depressive symptoms among older couples, testing social participation as a key mediating mechanism. Methods: Using a multistage, stratified probability sampling method, data were drawn from 4878 heterosexual married couples participating in the 2013, 2015, and 2018 waves of the China Health and Retirement Longitudinal Study. A longitudinal dyadic analysis was conducted using structural equation modeling to test an Actor-Partner Interdependence Mediation Model. Results: For both husbands and wives, their own internet use was associated with lower depressive symptoms, a relationship fully mediated by their own increased social participation (actor-actor effects). Crucially, significant asymmetric partner effects emerged. A husband's internet use was associated with a substantial reduction in his wife's depressive symptoms ( Conclusions: The mental health benefits of digital engagement extend beyond the individual user to their spouse, operating through enhanced social participation. These findings underscore the importance of dyadic, gender-sensitive approaches when developing interventions to promote digital literacy and social engagement to improve well-being in later life.