Smartphone use and teen mental health are increasingly linked as new research, lawsuits, and school policies reshape how families and institutions respond.
The age of the smartphone is not ending anytime soon, not least because the multibillion-dollar smartphone industry has a vested interest in ensuring that it continues. The Pew Research Center reported that teenage smartphone access rose from 37 percent in 2012 to 95 percent in 2024, and young adults — defined as anyone between the ages of 18 and 29 — consistently rank as the most active of all internet users. As of a few years ago, Gallup found that the average teenager in the United States spent about 4.8 hours a day on social media sites, with much of that screen time occurring, according to other research, during school hours.
And yet it seems simultaneously clear that when it comes to all smartphone users, including members of older generations but particularly those raised on a smart device, a major reckoning is finally at hand. Since 2023, more than 30 states have instituted partial smartphone restrictions or so-called bell-to-bell bans that prohibit smartphone use during school hours. Overseas, Australia’s government has gone so far as to ban social media for children under 16. (More than half a dozen countries are considering similar measures.)
And in Silicon Valley, tech titans like Meta, Google and Snap are facing a barrage of lawsuits — thousands in total — accusing them of deliberately preying upon vulnerable kids. “These companies built machines designed to addict the brains of children,” Mark Lanier, a plaintiff’s attorney, has said in a case against Meta and YouTube. “And they did it on purpose.” (A jury found both companies negligent.)
At the same time, what was once a steady drip of academic literature on the dangers of the smartphone has widened into a torrent. In recent years, for example, we have learned that smartphone use can lead to disturbances in “multiple cellular biological processes” in adolescents, while prolonged screen time may negatively affect parts of young brains that govern decision-making and impulse control. We have been told that people who receive a smartphone before age 13 experience higher levels of “detachment from reality” and diminished self-worth, and that heavy use can lead to cognitive impairment, obesity and hand pain.
These effects have inspired books like The Anxious Generation: How the Great Rewiring of Childhood Is Causing an Epidemic of Mental Illness, by New York University professor Jonathan Haidt, whose central thesis — that children have been unwillingly recruited as “test subjects for a radical new way of growing up, far from the real-world interactions of small communities in which humans evolved” — has been adopted as a rallying cry by parents everywhere.
In 2025, Madeleine George, a public health expert at RTI International, an independent research group, helped conduct a meta-analysis of 32 studies on the relationship between social media restriction and well-being. The upshot, she told me, was that staying offline yields “small but consistent positive effects.” She emphasized that the overall findings “masked a lot of variability” — many young people are able to enjoy a reasonably healthy relationship with their phone.
California Social Media Restrictions Target Teen Mental Health
