Age Limits Alone Won't Fix Smartphone Risks, Suggests Children's Hospital of Philadelphia Study

Researchers say removing smartphones from teens' bedrooms at night and limiting daily use is critical

PHILADELPHIA, June 8, 2026 /PRNewswire/ -- Researchers at Children's Hospital of Philadelphia (CHOP), in collaboration with the University of California, Berkeley and the University of Pennsylvania Perelman School of Medicine, found that a year after receiving their first smartphone at age 13, teens at 14 who spent significant time on their phones were more likely to experience depression, obesity, and insufficient sleep. The study was published today in JAMA Pediatrics.

Ran Barzilay, MD, PhD, the study's senior author and a child-psychiatrist with the Youth Suicide Prevention, Intervention and Research Center at CHOP, and Ziv Bren, MD, the study's lead author and a pediatrician postdoctoral research fellow at CHOP, expanded upon Barzilay's previous smartphone research. Last year, Barzilay and his collaborators reported that teens from the Adolescent Brain Cognitive Development study (ABCD) who acquire their first smartphone by age 12 are at greater risk of mental health issues and insufficient sleep than those who still remained "smartphone-free" at age 13.

In this new study, Barzilay and his team followed the "smartphone-free" cohort from age 13 to 14. The researchers looked at whether getting a smartphone around age 13 affected depression, obesity, or sleep one year later.

Of the 1,959 teens studied, 1,230 obtained a smartphone between the ages of 13 and 14 while 729 did not. Compared to those who did not acquire a smartphone, those who did acquire a smartphone at age 13 were at risk for insufficient sleep by age 14.

Researchers found that simply acquiring a smartphone at age 13 was not associated with depression at age 14; in contrast to first acquiring a smartphone at age 12, which was linked with adverse mental health a year later. The research suggests that by age 13 teens may be more emotionally ready to receive their first smartphone without it automatically harming their mental health.

However, when examining intensity of smartphone use, the researchers found that duration of time on smartphone and nighttime access are key factors that contribute to overall wellness. For children who had smartphones by age 14, using them for more than 5 hours a day was linked to more than twice the chance of depression and obesity, and double the chance of not getting enough sleep, compared with using them 2 hours or less a day. The study did not examine which specific phone activities (like gaming or social media) might be harmful.

"A simple habit appeared to reduce adverse outcomes. Kids who kept their smartphone devices outside the bedroom at night were less likely to report insufficient sleep, suggesting that removing them from bedrooms makes an impact on teen wellness," said Barzilay. "When considering the findings of this paper alongside our previous work, we can cautiously say that smartphone acquisition at age 13 appears safer than at or before age 12. However, even at age 13, our findings provide evidence informing parents and clinicians that it's important to introduce a smartphone with clear rules and supervision. We encourage families to set daily limits on smartphone use and remove them from their children's bedrooms at night."

Barzilay said the team will continue to evolve their research with an eye towards better understanding the impact of smartphone use, and specific types of use on children's and teen's wellness.

The research was supported by the Huo Family Foundation and the from the National Institute of Mental Health (R01MH134886).

Barzilay et al. "Smartphone Acquisition and Use at Age 13 and Their Associations with Health Outcomes at Age 14." JAMA Peds. Online June 8, 2026. DOI: 10.1001/jamapediatrics.2026.2118

Contact: Kaitlyn Dvorin
Children's Hospital of Philadelphia
(610) 618-0542 
[email protected]

SOURCE Children's Hospital of Philadelphia