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JAMA, the Journal of the American Medical Association, recently published the first-ever longitudinal cohort study investigating whether use of new technologies by adolescents leads, over time, to an increase in symptoms of ADHD. The study found that teens who reported not engaging in media use at a high frequency had a lower rate of developing ADHD symptoms (4.6 percent) than did teens who had engaged in at least seven activities (9.5 percent). In other words, the risk of developing ADHD symptoms more than doubled with high use of screens. (Kids who already had high levels of ADHD symptoms at enrollment were excluded from the study.)
But maybe the most interesting finding is that not all screen activities had equal effects. For example: Playing video games with family had no significant association with the development of ADHD symptoms, while playing video games alone (even if playing with other people online) had a strong association with subsequent ADHD symptoms.
One of several reasons this study is so important is that it was a longitudinal cohort study, in which researchers followed the same group of kids over time. That’s a much more powerful tool than a cross-sectional study, in which researchers just ask kids at one point in time what they’re doing, and then make correlations with other characteristics of those kids. In a cross-sectional study, it’s hard to say which came first: Did ADHD symptoms come first and cause kids to look at screens more, or were certain kids already looking at screens more and then develop ADHD? A longitudinal cohort study allows researchers to make better inferences about cause-and-effect, because you can at least determine—as these researchers did—which came first, the chicken or the egg. Or in this case, the screen time or the ADHD symptoms.
Bottom line: This study is additional evidence that excessive use of some new technologies may indeed increase symptoms of ADHD. In which case, we parents need to know: What is “excessive use”? And which technologies pose the greatest risk?
Combining this study with the current recommendations of the American Academy of Pediatrics regarding screen time, the following conclusions make sense:
- Limit screen time at night. If your kid isn’t getting enough sleep because they’re up late at night playing Fortnite or looking at their friend’s Instagram, they’re spending too much time online. By 9 p.m., at the latest, your kid’s device should be switched off and plugged into the charger.
- Prioritize school work. No YouTube, no social media, and no video games until the homework is done.
- Prioritize the family. The Academy recommends carving out "media-free times together." When you are with your child, you should be listening to her, and she should be listening to you, not watching YouTube.
- Prioritize genuinely-social screen time over solo screen time. Playing a video game with your son—shoulder to shoulder in the same room—may be a better choice than allowing your son to play a video game online with friends across town, or with ‘friends’ in Singapore whom he has never met.
- Practice what you preach: if you don’t want your kid to be checking their phone at 2 a.m., then you probably shouldn’t be checking your phone at 2 a.m. either.
