RESUMEN
BACKGROUND: Rural left-behind adolescents are more vulnerable to Internet addiction and depressive and anxious symptoms due to the lack of family support and parental supervision. This study was the first to investigate the longitudinal relationships between Internet addiction and depressive and anxious symptoms and to examine the mediating roles of resilience and friendship quality in rural left-behind adolescents. METHODS: Included in this study, which was from a longitudinal study conducted five times over 2 years, were 1001 rural left-behind adolescents. The internationally used scales for depressive and anxious symptoms, Internet addiction, resilience and friendship quality were administered. A structural equation model was used for analysis. RESULTS: The prevalence of Internet addiction, depressive and anxious symptoms among rural left-behind adolescents were 17.7%, 35.8% and 27.6%, respectively. Internet addiction predicted the later depressive and anxious symptoms (ß = 0.200, 95% confidence interval [CI]: 0.116-0.274 and ß = 0.263, 95% CI: 0.188-0.330). Resilience acted as an independent mediator in the relationships between Internet addiction and depressive and anxious symptoms (ß = 0.037 and 0.034, P < 0.01). Resilience and friendship quality played a chain-mediating role on the longitudinal relationships between Internet addiction and depressive and anxious symptoms (ß = 0.011 and 0.010, P < 0.001). The mediating effects accounted for 24.0% and 16.7% of the total effects, respectively. CONCLUSION: Resilience and friendship quality play an independent or chain-mediating role in longitudinal relationships between Internet addiction and depressive and anxious symptoms. The findings inform targeted intervention strategies to improve the mental health of left-behind adolescents.