American teenagers love their screens. Teens between 13 and 18 years old spend over six hours every day on smartphones, computers, tablets, and the like, well over the two-hour limit recommended by the American Academy of Pediatrics.
Health experts have been sounding the alarm about the pitfalls of too much screen time—including increased risk of obesity, depression, anxiety, and sleep disorders. Now a study published Tuesday (July 17) in the Journal of the American Medical Association suggests that frequent use of digital media by adolescents may also increase their odds of developing symptoms of attention deficit/hyperactivity disorder, or ADHD.
Previous research has linked television and video games consumption in teens with slightly higher risks of developing ADHD, a brain disorder that makes people more likely to act impulsively and have trouble with concentration. But few studies have looked at the possible connection between ADHD and the use of contemporary digital media platforms, like social media or video streaming services.
The study, conducted by a team of scientists from California, followed 2,587 students between 15 and 16 years old across 10 public high schools in Los Angeles County for two years. At the outset of the study, none of the students had ADHD symptoms. The researchers assessed the teens’ frequency of screen use, asking them about how often they engaged in 14 kinds of online activities, ranging from texting to using social media to streaming videos, monitoring them every six months between 2014 and 2016.
By 12th grade, teens who reported using digital media most frequently were also more likely to report having symptoms of ADHD. How much more likely? The researchers found that 10.5% of the 51 kids who reported using all 14 platforms multiple times a day said they had ADHD symptoms by 12th grade. Among the 495 students who were not frequent users of any digital activity, only 4.6% showed ADHD symptoms. (The kids who reported doing any of the 14 online activities multiple times a day were defined as “frequent” users.)
The authors of the study note that the study doesn’t prove causation—meaning that it’s not clear whether excessive screen time causes ADHD symptoms, or if teens who display symptoms of ADHD are more likely to spend time on their digital devices. The study authors also note that ADHD symptoms are not the same as an ADHD diagnosis. Still, the study offers one more reason for parents to keep an eye on their teens’ digital habits.