Prolonged mobile phone use is associated with depressive symptoms in Chinese adolescents

Background: Prolonged screen time has negative impacts on health and well-being. This study examined the association between the duration of mobile phone use (DMPU) and depressive symptoms in a large sample of Chinese adolescents. Methods: 11,831 adolescent students participated in the baseline Shandong Adolescent Behavior and Health Cohort (SABHC) survey in Shandong, China in 2015. A self-administered questionnaire was used to measure DMPU on weekdays and the weekend, sleep, mental health, and family environment. The Center for Epidemiologic Studies Depression Scale (CES-D) and Youth Self-Report (YSR) depression scales were used to assess depressive symptoms. Results: The mean age of participants was 15.0 (SD = 1.5) and 51% were male. The prevalence of depressive symptoms increased with prolonged DMPU. After adjusting for adolescent and family covariates, DMPU >= 2 h/ day on weekdays (OR = 1.78, 95%CI = 1.48-2.15) and >= 5 h/day on the weekend (OR = 1.67, 95%CI = 1.41-1.98) was associated with increased risk of depressive symptoms as assessed by CES-D. The DMPU-depression association was found to be partially mediated by short sleep duration or insomnia. Similar associations were observed for depression as assessed by YSR. Study limitation: This is a cross-sectional survey. Mobile phone use and depressive symptoms were measured by self-report. Conclusions: Prolonged mobile phone use of >= 2 h on weekdays and >= 5 h on the weekend is associated with an increased risk of depressive symptoms. The association appears to be partially mediated by sleep disturbances.