More Than Four Hours of Smartphone Use a Day Harmful to Teens

Significantly higher risk seen for stress, suicidal ideation, and substance use

By Lori Solomon HealthDay Reporter

THURSDAY, Dec. 7, 2023 (HealthDay News) — More than four hours of smartphone use per day negatively impacts behavioral health outcomes for adolescents, according to a study published online Dec. 6 in PLOS ONE.

Jong Ho Cha, from the Hanyang University Medical Center in Seoul, South Korea, and colleagues examined the association between smartphone use and adverse behavioral health outcomes. The analysis included data from 40,998 adolescents participating in the nationwide Korea Youth Risk Behavior Web-based Survey (2017 and 2020).

The researchers found that adolescents’ mean smartphone usage time in 2020 increased from 2017 (weighted percent of more than two hours/day: 64.3 versus 85.7 percent). After more than four hours/day, the curvilinear relationships between smartphone usage time and adverse health outcomes were prominent. There were no increased adverse health outcomes observed among adolescents using smartphones two to four hours/day versus nonusers, except for smartphone overdependence. However, there were significant associations between using a smartphone more than four hours/day and stress perception (odds ratio, 1.16), suicidal ideation (odds ratio, 1.22), and substance use (alcohol: odds ratio, 1.66) after propensity score matching.

“These results can help establish smart device usage guidelines and education programs for appropriate media use,” the authors write.