A cross-lagged study of the associations among problematic smartphone use, depressive symptoms, and suicidal ideation in chinese university students

The present study aimed to investigate the longitudinal and reciprocal relationships among problematic smartphone use (PSU), depressive symptoms (DS), and suicidal ideation (SI) in Chinese university students. Using a cross-lagged design, the Mobile Phone Addiction Inventory Scale, the Center for Epidemiologic Studies Depression Scale, and the Self-Rating Idea of Suicide Scale as research instruments, 194 university students completed a questionnaire four consecutive times. June of Year 1, December of Year 2, June of Year 2, and December of Year 3 of their college study. We refer to these as the Time 1 (T1), Time 2 (T2), Time 3 (T3), and Time 4 (T4) assessments, respectively. The levels of PSU and DS fluctuated significantly over time. DS at T1 was significantly predicted to influence SI at T2 (β = 0.17, p < .05); DS at T3 was significantly predicted by PSU and by SI at T2 (respectively, β = 0.30, p < .05; β = 0.21, p < .05); DS at T2 significantly predicted PSU at T3 (β = 0.14, p < .05); and DS at T3 significantly predicted SI at T4 (β = 0.14, p < .05) in the cross-lagged pathway. DS at T3 fully mediated the relationship between PSU at T2 and SI at T4 (indirect effect: β = 0.133, 95% CI = [0.063, 0.213]). The results suggest that there is a reciprocal relationship between PSU and DS and, furthermore, that DS plays an important mediating role between PSU and SI. Our results suggest the importance of early identification and treatment of SI. Timely reduction of PSU and improvement of DS among university students may help prevent SI.