A study led by researchers at Children’s Hospital of Philadelphia (CHOP), in collaboration with the University of California, Berkeley and Columbia University, has found a connection between smartphone ownership in early adolescence and increased risks of depression, obesity, and insufficient sleep. The research, published in the journal PEDIATRICS, examined data from over 10,000 adolescents across the United States who participated in the Adolescent Brain Cognitive Development study between 2018 and 2021.
The study considered several factors including age of first smartphone acquisition, demographic and socioeconomic background, other device ownership, pubertal development, and parental monitoring. It did not examine which specific smartphone features might be responsible for negative health outcomes.
Researchers found that owning a smartphone at age 12 was associated with higher risks of depression, obesity, and insufficient sleep. Additionally, those who received smartphones at younger ages faced even greater risks for obesity and insufficient sleep. Adolescents who acquired a smartphone after age 12 also showed increased risk for mental health problems and poor sleep by age 13 compared to peers without phones.
Ran Barzilay, MD, PhD, lead author of the study and child-psychiatrist at CHOP’s Youth Suicide Prevention, Intervention and Research Center stated: “Our findings suggest that we should view smartphones as a significant factor in teen health, approaching the decision to give a child a phone with care and considering potential impacts on their life and health.” He added: “We are not claiming smartphones are detrimental to all adolescents’ health; rather, we advocate for thoughtful consideration of the health implications, balancing both positive and negative consequences. For many teens, smartphones can play a constructive role by strengthening social connections, supporting learning, and providing access to information and resources that promote personal growth. Likewise, some families may view a smartphone as a necessity for safety or communication.”
Barzilay also said: “Most probably, all teens will eventually have a smartphone. Once this happens, it is advisable to monitor what our children do on their phones, ensuring they’re not exposed to inappropriate content and that smartphones don’t disrupt sleep. 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.”
The researchers recommend establishing clear family rules before giving children smartphones—such as agreements on usage terms—and setting guidelines about where phones can be used (for example: bedrooms or dinner tables). They also advise adjusting privacy settings to block inappropriate content while regularly discussing any issues related to phone use within families.
Barzilay recommends caregivers consult guidance from organizations like the American Academy of Pediatrics or American Academy of Child and Adolescent Psychiatry when managing adolescent smartphone use.
The full study is available online: https://doi.org/10.1542/peds.2025-072941.
