Cell phone use is good for teens’ mental health — but only this many hours, study finds

Contrary to what countless media reports have warned parents, extended screen time isn’t all bad.

The latest research has revealed that smartphone-toting teenagers may benefit from spending time on their devices — but only to an extent.

The new study, published Wednesday in the journal PLOS ONE, shows that adolescents who used their phones for one to two hours per day had a lower risk of depression, suicidal thoughts, sleep issues, stress and alcohol addiction compared to those who didn’t use a phone at all.

However, those who spent more than four hours on their smartphones suffered higher rates of these mental health problems and substance abuse — up to a 22% greater risk than moderate device users.

“Regarding social purposes, one to two hours of usage time was protective against suicide attempts,” the study authors wrote in their report. “From our results, using smartphones for less than two hours a day even seems beneficial for mental health outcomes compared to non-use.”

Between 2017 and 2020, some 50,000 Korean youth answered two sets of extensive questionnaires, one to survey their physical and mental health and another to gauge their smartphone use. Researchers at Korea’s Hanyang University used the data to analyze the relationship between smartphone usage and health outcomes, adjusting for factors such as age, sex and socioeconomic status.

While previous studies have shown that too much screen time can have negative effects on a user’s health and well-being, researchers found that small amounts of phone use as a young adult can have “beneficial” effects. They found that two hours or less of smartphone time for social purposes can help teens combat loneliness and isolation — but beyond that threshold could signal mounting despair.

Compared to teens who claimed not to use their phones recreationally, those who engaged with social media for less than two hours per day were 30% less likely to be stressed, 27% less likely to have sleep issues, 38% less likely to be depressed, 43% less likely to be suicidal and 47% less likely to be abuse alcohol.

Some of those benefits held up with slightly increased use. Again, compared to no activity at all, teens who used their phones between two and four hours daily were 29% less likely to be stressed, 34% less likely to be depressed, 40% less likely to be suicidal and 27% less likely to be addicted to alcohol.

However, beyond four hours of social screen time manifested increasing negative effects. Researchers found that when phone usage reaches between four and six hours or more per day, teens were more likely to endure poor mental health, stress, obesity, depression and suicidal thoughts.

This finding, the authors wrote, “corresponds with previous studies” showing too much screen time can be detrimental to mental health.

Teens who fail to nip their phone use in the bud risk similar issues in adulthood. According to data compiled by Statista, the average American adult spent just over four-and-a-half hours on their phones daily in 2023, while one recent study found that the most device-addicted are more likely to be diagnosed with borderline personality disorder symptoms and psychological distress.