Internet use time and mental health among rural adolescents in China: A longitudinal study

Background: The digital divide between urban and rural adolescents is widening. Many existing studies have found an association between internet use and adolescent mental health, but few use longitudinal data to focus on rural adolescents. We aimed to identify the causal relationships between internet use time and mental health in Chinese rural adolescents. Methods: Using a sample of 3694 participants (aged 10-19) from the 2018-2020 China Family Panel Survey (CFPS). Fixed effects model, mediating effect model and instrumental variables method was used to evaluate the causal relationships between internet use time and mental health. Results: We find that more time spent on the internet has a significant negative effect on participants' mental health. This negative impact is stronger in female and senior students groups. Mediating effects analysis suggests that more time spent on the internet increase risk of mental health problems by reducing sleep duration and parent-adolescent communication. Further analysis find that online learning and online shopping is associated with higher depression scores, while online entertainment with lower depression scores. Limitations: The data do not investigate the specific time spent on internet activities (e.g., learning, shopping, and entertainment), and the long-term impacts of internet use time and mental health have not been tested. Conclusions: Internet use time has a significant negative impact on mental health by crowding out sleep duration and parent-adolescent communication. The results provide an empirical reference for the prevention and intervention of mental disorders in adolescents.