The earlier a kid is hooked on a smartphone, in other words, the worse their physical and mental health outcomes are likely to be. Similarly, the study also found that every year before 13 that a child received a smartphone was associated with a greater likelihood of poorer mental health and well-being. In follow-up research, Barzilay hopes to explore more specific features of smartphone usage to determine their link to mental health outcomes. “It’s critical for young people to have time away from their phones to engage in physical activity, which can protect against obesity and enhance mental health over time,” Barzilay said in a statement about the work. More on mental health: Here’s an Interesting Theory About Why Kids’ Test Results Have Fallen to Their Lowest Point in Two Decades