Smartphone Dependency Development in Adolescents: Contemporaneous and Lagged Effects of Risk Factors, and Moderating Effects of Protective Factors

This study investigated smartphone dependency trajectories and their associations with predictive variables: gender, family socioeconomic status, and parental smartphone dependency. In addition, we examined both contemporaneous and lagged effects of risk factors (depression, negative peer relationship) and the moderating effects of protective factors (happiness, positive peer relationship). The KCYPS 2018 data for grades 7 to 11 were analyzed using the Latent Growth Modeling method. The findings revealed that smartphone dependency increased during middle school but no significant change in high school. Parental smartphone dependency was the only predictor of initial levels. Depression and negative peer relationships consistently predicted smartphone dependency. Depression showed lagged effects at the beginning of middle and high school, and negative peer relationships exhibited a lagged effect in the third year of middle school. Happiness significantly moderated the impact of depression on smartphone dependency, unlike positive peer relationships, which did not moderate the impact of negative peer relationships. These results highlight the need for tailored intervention strategies that address the complex risk factors influencing adolescents??smartphone dependency.