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.

​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. 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.