Association between Internet addiction and mental health problems among Chinese adolescents in the post-COVID-19 pandemic era: a propensity score matching study

BACKGROUND: Improving adolescent mental health is a priority for public health, with Internet addiction (IA) being notably linked to these problems. In the post-pandemic era, increased screen time and social isolation persist, albeit in a more normalized form, potentially continuing to affect adolescent mental health. The current study aims to examine the relationship between IA and mental health problems among Chinese adolescents in the post-COVID-19 pandemic era. METHODS: A cross-sectional survey was conducted in two cities of Henan Province, China, between April and May 2023. A total of 8176 junior high school students were recruited from 6 schools using a stratified random cluster sampling method. The associations between IA and mental health problems were assessed using ordinary least squares model and propensity score matching, specifically employing 1:1 nearest neighbor matching, radius matching, and kernel matching. The average treatment effect on the treated (ATT) was reported. RESULTS: The detection rate of IA was 19.37% (1584/8176) in this study . Before matching, IA was correlated with elevated levels of depression (β = 2.766, p < 0.001) and anxiety (β = 2.338, p < 0.001), after adjusting for other variables. After matching, participants exhibiting IA were more likely to experience depression and anxiety compared to those who were not addicted. Nearest Neighbor Matching: ATT for depression and anxiety was 3.026 (95% CI: 2.609 ~ 3.443) and 2.472 (95% CI: 2.096 ~ 2.848); Kernel Matching: ATT for depression and anxiety was 2.980 (95% CI: 2.654 ~ 3.396) and 2.448 (95% CI: 2.072 ~ 2.824); Radius Matching: ATT for depression and anxiety was 2.886 (95% CI: 2.470 ~ 3.302) and 2.349 (95% CI: 1.973 ~ 2.725). CONCLUSION: IA was associated with depression and anxiety among Chinese adolescents in the context of the post-COVID-19 pandemic era. Policymakers, parents, and school personnel should prioritize addressing IA to decrease mental health problems in this population.