Teen phone rules may matter as much as age, study finds
A JAMA Pediatrics study links heavy smartphone use at 14 to depression, obesity and poor sleep, while age 13 ownership alone showed narrower risks.
By Tom Brennan · Health & Medicine Correspondent
3 min read
Giving a teenager a first smartphone at 13 was tied to later sleep problems, but the amount of use appeared to carry broader health risks, according to researchers at Children’s Hospital of Philadelphia. The findings add weight to advice that families pair phone ownership with limits on daily use and nighttime access.
The study, published in JAMA Pediatrics, was conducted by CHOP researchers with collaborators at the University of California, Berkeley, and the University of Pennsylvania Perelman School of Medicine. It followed 1,959 adolescents who had not yet received a smartphone at age 13 and examined their health outcomes at age 14.
Among those teens, 1,230 got a smartphone between ages 13 and 14, while 729 did not, according to CHOP. Compared with adolescents who remained without a smartphone, those who received one around age 13 had a higher likelihood of insufficient sleep one year later.
Use level showed wider links to health
The researchers said phone ownership at age 13, by itself, was not associated with depression at age 14. CHOP contrasted that result with earlier work by senior author Ran Barzilay and colleagues, which found that children who had their first smartphone by age 12 faced higher risks of mental health issues and inadequate sleep than peers who still did not have a phone at 13.
Barzilay’s team said the newer findings suggest adolescents may be better prepared emotionally for a first smartphone at 13 than at 12 or younger. The study did not establish that phones caused the outcomes, and the findings point to patterns of association rather than a full account of why those differences appeared.
Time spent on the device was a major factor in the analysis. Among adolescents who had smartphones by age 14, those using them for more than five hours a day had more than twice the chance of depression and obesity, and twice the chance of insufficient sleep, compared with teens using phones two hours a day or less, according to the study.
The researchers did not identify which smartphone activities were linked to possible harm. The study did not separate effects from gaming, social media, messaging or other uses.
Nighttime access drew attention
CHOP said where teens kept their phones at night also mattered. Adolescents who did not keep smartphones in their bedrooms overnight were less likely to report too little sleep, according to Barzilay, a child psychiatrist with CHOP’s Youth Suicide Prevention, Intervention and Research Center.
Barzilay said the findings support a cautious interpretation: receiving a smartphone at 13 may be safer than receiving one at 12 or earlier, but families should not treat age as the only safeguard. He urged parents and clinicians to use clear rules, supervision, daily use limits and a policy of keeping phones out of bedrooms overnight.
The study’s lead author was Ziv Bren, a pediatrician and postdoctoral research fellow at CHOP. Barzilay said the research team plans to continue studying how smartphone use, including specific kinds of use, relates to children’s and teens’ well-being.
This story draws on original reporting from Medical Xpress.