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Smartphone ownership in early adolescent years is tied to risk factors for heart disease, diabetes and cancer
Julia Mustoin New YorkMonday 01 December 2025 19:44 GMTComments
CloseYour Child's Smartphone Could Be Destroying Their Mental Health
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If you think your preteen’s smartphone is harming their health, you may be right.
A new study of more than 10,000 U.S. adolescents has found that kids who own a smartphone before the age of 12 are at an increased risk of depression, obesity and insufficient sleep compared to their peers who don’t have smartphones — contradicting a smaller Stanford Medicine study from 2022 that found no connection between the age kids acquired their first cell phone and sleep patterns or depression.
All three conditions are risk factors for life-threatening illnesses that impact millions of Americans each year, such as heart disease, cancer and diabetes.
Those who acquired a smartphone between the ages of 12 and 13 also had a raised risk of mental illness and insufficient sleep at age 13 compared to those without the devices.
Previous studies have shown ties to negative impacts on adolescent mental health and identified health harms from screen use, but the new study did not look into which specific features of smartphone use are linked to poorer health.
open image in galleryKids with a smartphone before the age of 12 are at an increased risk of depression, obesity and poor sleep, experts warn (Getty Images/iStock)"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," Dr. Ran Barzilay, a child psychiatrist at the Children's Hospital of Philadelphia, said in a statement.
More kids have smartphones now
Barzilay and others from California’s U.C. Berkeley and New York City’s Columbia University reviewed data collected between 2018 and 2020 from the Adolescent Brain Cognitive Development study: the largest long-term look at children’s brain development in America to date.
They looked at smartphone ownership, the age the kids first got the phones, what other devices they owned, when the kids hit puberty, how parents monitored use and socioeconomic and demographic variables.
Of the 10,588 participants, 6,739 owned a smartphone.
Significantly more children and teens now have their own mobile device now than just a decade ago, including 51 percent of children ages eight and younger, according to data released earlier this year from Common Sense Media. That tally was just 45 percent in 2017.
More than 60 percent of parents of kids between the ages of 11 and 12 said their child has a smartphone, a Pew Research Center survey from October found.
open image in galleryKids can safely have smartphones, but researchers stress the importance of regulated use (Getty Images)A healthy balance
But, parents shouldn’t take away their kids’ phones just yet, and smartphones have been shown to help kids socialize and are important tools in emergencies.
"We're 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,” added Barzilay.
Barzilay and the researchers issued new recommendations for families whose children have smartphones.
Those include establishing clear usage terms before giving a child a phone, setting guidelines for phone use in the bedroom, at dinner and during homework and adjust privacy and content settings
"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," Barzilay said.
In the future, the researchers plan to investigate specific aspects of smartphone use, such as app types and usage patterns that negatively impact health. They hope to study children who get smartphones before the age of 10.
But, while kids may not need to give up their phones, Barzilay also stressed the importance of putting them down.
"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,” he said.
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