Developmental Trajectories of Adolescent Internet Addiction: Interpersonal Predictors and Adjustment Outcomes

Despite the burgeoning literature on adolescent internet addiction (IA), the majority of studies have relied on cross-sectional designs and variable-centered analytical approaches. Therefore, little is understood about the heterogeneous developmental trajectories of adolescent IA as well as its antecedents and outcomes. This longitudinal study adopted growth mixture modeling (GMM), a person-centered approach, to identify the distinct trajectories of IA among adolescents during a three-year period. We further examined the interpersonal predictors along with a series of outcomes of different trajectories. Participants included 1,365 Chinese adolescents (M_age = 14.68 years, SD = 1.56; 46.8% girls) from two junior high schools and two senior high schools. The GMM results indicated three distinct trajectories: low-increasing (56.7%), moderate-declining (37.6%), and high-declining (5.7%) groups. In terms of interpersonal predictors, adolescents who reported poorer relationships with their parents, teachers, and schoolmates were more likely to belong to the high-declining and moderate-declining groups. In terms of outcomes, the high-declining and moderate-declining groups exhibited an increase in mental health problems (i.e., more depressive symptoms, lower self-esteem, and lower subjective well-being) and delinquent behaviors, even after controlling for their baseline levels. These findings highlight the heterogeneity of IA trajectories among adolescents, the predictive role of interpersonal factors, and different adjustment outcomes associated with IA trajectories. Therefore, prevention and intervention programs involving interpersonal relationships may be promising for adolescents at high or moderate risk of IA.