Abstract
BACKGROUND: Despite prior studies have shown the impacts of different types of social media use on adolescent's mental health can vary, little is known about why and when these differences occur. Thus, this study investigated the effects of different types of social media use-public active use, private active use, and passive use-on adolescent mental health through Self-Determination Theory's three basic psychological needs (autonomy, relatedness, and competence), and how these effects are shaped by the quality of offline relationships. METHODS: A two-wave panel study with five-month interval was conducted among 343 randomly selected Chinese adolescents aged 11 to 17 (from grade 7 to grade 11). RESULTS: Findings showed that no direct effects of any type of social media use on mental health outcomes over time, while private active social media use significantly predicted the fulfillment of relatedness needs and positively contributed to subsequent life satisfaction. The "poor get richer" and "rich get richer" of social media use hypotheses were supported. Specifically, for adolescents with low-quality offline relationships, public active social media use promoted the satisfaction of competence needs and thus decreased depression, and promoted competence and autonomy satisfaction and thus increased life satisfaction. For adolescents with high-quality offline relationships, private active social media use facilitated relatedness satisfaction, subsequently enhancing life satisfaction. CONCLUSION: This study introduces an explanatory boundary condition for the diversity of psychological reactions stemming from different types of social media use, and underscores the significance of personalized guidance for adolescents' social media use.