The relationship between digital health literacy and problematic mobile social media use among adolescents: the chain mediating role of physical activity and social–emotional competence

Objective: With the rapid expansion of digital technologies and the global increase in social media use, this study aimed to investigate the relationship between digital health literacy (DHL) and problematic mobile social media use (PMSMU) among adolescents, as well as the underlying mechanisms. Methods: A total of 555 adolescents were surveyed using the eHealth Literacy Scale (eHEALS), the Problematic Mobile Social Media Usage Assessment Questionnaire, the Physical Activity Rating Scale (PARS-3), and the social-emotional competence scale. Results: < 0.001). Mediation analysis revealed three significant indirect pathways: PA mediated the relationship (21.43%), SEC mediated it (10.71%), and a sequential pathway through PA and SEC also emerged (5.36%). Conclusion: DHL not only directly predicts PMSMU but also indirectly predicts it through the independent and chain mediating effects of PA and SEC. Among these indirect pathways, PA emerged as the most influential mediator.