The longitudinal mediating effect of rumination on the relationship between depressive symptoms and problematic smartphone use in Chinese university students: A three-wave cross-lagged panel analysis

Although previous studies have considered rumination a possible mediator of the relationship between mental health and problematic smartphone use (PSU), few prospective studies have been conducted, limiting the ability to draw causal inferences. Therefore, the current study aimed to examine the mediating role of rumination on the depression-PSU relationship using three-wave cross-lagged panel models (CLPMs) with longitudinal data. A sample of 321 medical students from China Medical University completed three waves of online measures of depressive symptoms, rumination, and PSU. The three-wave CLPMs were constructed to examine the mediating role of rumination. Our results demonstrated that depressive symptoms were bidirectionally related to rumination, and that rumination was bidirectionally related to PSU. The reciprocal CLPM suggested that depressive symptoms at Time 1 positively affected PSU at Time 3 via rumination at Time 2. The indirect effect was significant, with a path coefficient of 0.023 (95% CI: 0.004 to 0.042). Conversely, PSU at Time 1 positively affected depressive symptoms at Time 3 via rumination at Time 2, with a path coefficient of 0.015 (95% CI: 0.001 to 0.029). This prospective study provided empirical evidence of the influence of depression on PSU and vice versa among Chinese university students. It also highlighted the importance of rumination in the depression-PSU relationship, revealing a bidirectional mediating role of rumination. Additional large-scale multi-wave longitudinal studies are needed to verify our results.