Smartphone use, sleep, and mental health in Korean adolescents.

BACKGROUND: Studies have shown that problematic smartphone use is associated with poor sleep quality and poor mental health among adolescents. However, little is known about whether the moderate use of smartphone without addiction is associated with poor mental health and whether the association is independent of sleep quality.

OBJECTIVE: Using nationally representative data, this study examined the associations of smartphone use duration with sleep satisfaction and mental health conditions (generalized anxiety disorder [GAD], depressive symptoms, suicidal ideation, and suicidal attempts).

METHODS: We conducted a cross-sectional analysis of 51,718 Korean adolescents. Participants reported their average duration of smartphone use, sleep satisfaction, and symptoms of poor mental health. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the associations of smartphone use duration with sleep satisfaction and mental health outcomes, accounting for complex survey sampling and adjusting for potential confounders.

RESULTS: Prolonged smartphone use (≥420 vs. <180 min/d) was associated with higher odds of low sleep satisfaction (OR [95% CI]: 1.22 [1.14, 1.30]), GAD (1.27 [1.15, 1.41]), depressive symptoms (1.42 [1.32, 1.52]), suicidal ideation (1.36 [1.25, 1.48]), and suicidal attempts (1.70 [1.43, 2.02]). The positive associations with GAD, depressive symptoms, suicidal ideation and suicidal attempts persisted after additional adjustment for sleep satisfaction and after excluding participants at high risk of smartphone overdependency.

CONCLUSIONS: Our findings suggest that prolonged smartphone use is associated with poor mental health among Korean adolescents, independent of sleep satisfaction and even without problematic use.