The Critical Moderating Role of Cognitive Function: A Study on the Mechanisms of Digital Inclusion's Effect on Depression Among Older Adults (Preprint)

BACKGROUND Digital inclusion has become increasingly important in promoting healthy aging, yet its impact on mental health among older adults appears complex and heterogeneous. While existing research has identified associations between digital technology use and depression risk in older adults, the role of cognitive function as a moderator and the underlying mechanisms remain understudied. OBJECTIVE Data from the 2020 wave of the China Health and Retirement Longitudinal Study (CHARLS), a nationally representative survey of 18,673 Chinese adults aged 60 and above. METHODS We examined cognitive function's moderating role in the relationship between digital inclusion and depression risk. We constructed interaction effect models to test the moderation hypothesis and employed path analysis to investigate multiple pathways (direct effect, cognitive enhancement, and social participation) through which digital inclusion influences depression. RESULTS Cognitive function significantly moderated the relationship between digital inclusion and depression risk (β = -0.002, p < 0.05), with stronger protective effects observed among older adults with higher cognitive function. Path analysis revealed that digital inclusion affected depression through three main pathways: a direct pathway (accounting for 66.7% of the total effect), a cognitive function mediation pathway (8.3%), a social participation mediation pathway (8.0%), and a sequential mediation pathway through cognitive function and social participation (2.8%). The remaining 14.2% was attributed to unexplained mechanisms. CONCLUSIONS Our findings reveal a "cognitive threshold effect," suggesting that older adults require a baseline level of cognitive function to derive mental health benefits from digital participation. This study advances understanding of digital inclusion's differential impacts and mechanisms of action, supporting the development of cognitive-informed digital inclusion programs and suggesting the integration of cognitive training and digital skills development in mental health interventions for older adults.