Children are getting smartphones earlier and earlier, and new data raise serious concerns. Researchers analyzed information from more than 10,000 teenagers in a large brain development study. They found that simply owning a smartphone at age 12 was associated with significant health problems. The results were published in the journal Pediatrics, led by Ran Barzilay from the Children’s Hospital of Philadelphia.
By age 12, kids who had a smartphone faced more difficulties than their peers without one. The risk of depression increased by 31%, obesity by 40%, and lack of sleep by 62%. If a smartphone appeared earlier, the chances of excess weight and poor sleep rose an additional 8–9% for every year of earlier ownership. Even among those who did not have a phone at age 12, receiving it within the next year raised the likelihood of psychological issues and sleep problems at age 13 by 50–57%.
The explanation is straightforward: smartphones provide endless content, easily distracting from real life. Teenagers spend less time moving, go outside less often, and go to bed later. A small device in the pocket gradually replaces sports, face-to-face friendship, and healthy rest.
Researchers adjusted for many factors — family income, other devices in the home, puberty stage, and parental rules. The relationships remained significant.
Barzilay emphasizes that almost every teenager will eventually get a smartphone, but parents need to take it seriously: set rules, limit screen time, and encourage outdoor activity. This study is not about guilt — it offers strong arguments for conversations about digital parenting and may lead to new recommendations on the age for the first smartphone.