Get Your Teen Weekly Newsletter in your inbox! Sign Up
YourTeenMag Logo

Kids and Screens: Effects Of Screen Time On Brain Development

How does screen time affect kids’ brains? This is a question that plagues most parents… and brain science researchers.

Since 2013, the National Institutes of Health (NIH) has been conducting the Adolescent Brain Cognitive Development Study (known as the ABCD study) to better understand different aspects of adolescent cognitive, social, physical and emotional development. Researchers are working with more than 11,000 kids, ages 9 to 10, at 21 different sites across the country to track their development through young adulthood.

Kids, Screen Time, and the Brain

The $300 million study began as a way to analyze the impact of substance use on adolescent brains. But the initial research has broadened to include what many think of as a new drug of choice: screens.

Any parent who has asked their kid to put down a device already realizes the potential addictiveness of social media and video games. “One more second“ seems to be a constant refrain in my house, but it is never just one more second. Kids and screens are a real problem. And once screens get our kids’ attention, it can be nearly impossible for them to look away.

The concern many parents have about the impact of screen time on their kids’ brains has brought that aspect of the study to the forefront. Recently, NIH researchers presented initial findings from the brain scans of 4,500 participants and shared the results.

Moderate Screen Use Lowers Test Scores

Researchers from Canada looked at data from the first release of the ABCD study. They examined whether screen time affected performance on cognitive tests. For the study, parents answered questions about the amount of time their kids spent on screens, the amount of time they exercised each day, and the number of hours they slept each night.

The study found that kids who used screens recreationally for less than two hours each day performed better on cognition tests. Using screens for less than two hours, but not meeting the exercise or sleep recommendations, led to improved scores. Not surprisingly, cognition scores were better when participants met both the screen time and sleep recommendations. Kids who used screens for more than two hours, however, scored lower on the tests, even if they met the other guidelines.

Excessive Screen Use Alters the Brain

The initial data has also revealed another key finding: kids ages 9 to 10 who spend more than seven hours a day using smart devices or playing video games show a thinning of the outermost layer of the brain associated with processing sensory information. That thinning is a normal maturation process, as researcher Dr. Gaya Dowling describes, but researchers are seeing it earlier in kids who use devices often throughout the day.

Is the accelerated thinning of the cortex of the brain a bad thing? Is the thinning caused by screen time? At this point, the NIH researchers don’t know what these changes mean. They will release more data early in 2019. It will take years, however, to understand the full outcomes of this research.

Social Media Affects the Brain

Another component of the NIH study looks specifically at social media use. NIH researcher, Dr. Kara Bagot, scans teenagers’ brains while they look at images on Instagram. Based on her research so far, she believes social media can be addictive. It stimulates the release of dopamine, a brain chemical that contributes to feelings of pleasure and plays a role in addiction. Bagot suggests that the dopamine stimulated when teens use social media can make them more likely to use social media compulsively.

As digital natives, the first generation growing up with such ready accessibility to smart devices, our kids are literally living out a social experiment. The results of which may take years to fully understand. In the meantime, I’ll be setting timers for screen use and pulling out the family games we’ve accumulated over the years. Uno, anyone?

Catherine Brown writes about parenting, the arts, eating disorders, and body image for local and national publications. She is co-editor of Hope for Recovery: Stories of Healing from Eating Disorders and co-host of the podcast Eating Disorders: Navigating Recovery. You can find her at, on Facebook and on Instagram (catbrown_writer).

Related Articles