Study Shows Early Smartphone Use May Affect Kids’ Mental and Physical Health

A new study published in the journal Pediatrics is raising important questions for parents about when children should get their first smartphone. Researchers followed more than 10,500 kids from the Adolescent Brain Cognitive Development Study, the largest long-term study of child brain development in the United States. Their findings suggest that getting a smartphone before age 12 may come with significant health risks.

How Early Smartphone Access Affects Health

The study looked at children under age 12 and found that those who already had a smartphone were more likely to experience depression, obesity and poor sleep than those who did not yet have one.

Researchers also examined a group of children who did not have smartphones by age 12. One year later, the kids who had since acquired a phone were showing more mental health symptoms and worse sleep than those who still did not have one.

The younger the child was when they received a smartphone, the higher their risk for poor sleep and weight gain. Age truly mattered.

Why Smartphones Might Influence Mental Health

This study shows an association, not proven cause and effect. But the researchers point to existing evidence that helps explain the pattern.

Kids who have smartphones may spend more time sitting indoors, scrolling or gaming, and less time socializing face-to-face, being active and getting enough sleep. All of these are essential for healthy development. Adolescence is a sensitive window, and even small disruptions to rest, mood or routines can have long-lasting effects.

Experts agree that giving a child access to everything on the internet introduces risks. Parents also carry the responsibility of setting boundaries, using parental controls and teaching safe digital habits.

This research is not about blaming parents. Instead, it highlights the importance of being thoughtful about timing.

Why Sleep Is So Important

Sleep is one of the clearest areas where smartphone use can cause harm.

Another large study using the same national dataset found that most 11 to 12 year olds have an electronic device in their bedroom. Nearly 17 percent said they had been awakened by notifications in the past week.

Removing phones from bedrooms overnight is one of the simplest ways to support kids’ sleep and reduce health risks. Even for families who have already given their child a smartphone, creating phone-free sleep routines can make a meaningful difference.

What Parents Should Know

This new research shows that children who get a smartphone before age 12 may face higher risks of depression, poor sleep and weight gain. The median age for getting a first smartphone in the study was 11, meaning most families are navigating this decision earlier than ever.

Experts recommend that parents feel empowered to trust their instincts. Waiting until a child is older allows time for more maturity, better decision-making and clearer boundaries.

Giving a child a device does not guarantee long-term problems. But it does mean that families, schools and communities should take steps to support healthy technology use.

At Cline Medical Group, we stay on top of the latest research so you do not have to. If you have questions about child development, sleep, mental health or healthy routines, we are here to help guide your family every step of the way.

Source: https://publications.aap.org/pediatrics/article-abstract/doi/10.1542/peds.2025-072941/205716/Smartphone-Ownership-Age-of-Smartphone-Acquisition?redirectedFrom=fulltext