More than 4 hours of daily smartphone use associated with health risks for adolescents

In a new study of more than 50,000 Korean adolescents, those who used a smartphone for more than 4 hours per day had higher rates of adverse mental health and substance use. Jin-Hwa Moon and Jong Ho Cha of Hanyang University Medical Center, Korea, and colleagues present these findings in the open-access journal PLOS ONE on December 6, 2023.

Prior research has shown that smartphone use among adolescents has increased in recent years, and that this usage may be associated with higher risk of adverse health-such as psychiatric disorders, sleep issues, eye-related problems, and musculoskeletal disorders. However, growing evidence suggests that at least some daily internet usage may be associated with better physical and mental health for adolescents.

To deepen understanding of the relationship between adolescents’ use of smartphones and health, Moon, Cha and colleagues analyzed data on more than 50,000 adolescent participants in the ongoing Korea Youth Risk Behavior Web-based Survey collected in 2017 and in 2020. The data included the approximate number of daily hours each participant spent on a smartphone as well as various health measures. The statistical analysis employed propensity score matching to help account for other factors that could be linked to health outcomes, such as age, sex, and socioeconomic status.