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What you need to know about that study linking ADHD symptoms and digital media use

Joy Victory is Deputy Managing Editor of She tweets at @thejoyvictory.

ADHD symptoms and digital media

The big health news story on Wednesday — covered by the Los Angeles Times, CNN, NBC News, Newsweek, the Wall Street Journal, NPR, HealthDay and Reuters Health, among others — was a study looking at the relationship between “digital media use” (basically, going online) and ADHD symptoms in a group of Southern California teens.

The implication from some stories–the clickbait, in other words–is that using the internet too much can cause ADHD. Parents, you can take a deep breath and get back to scrolling through Facebook, the study did not show that, in spite of headlines like these:

Can Smartphones Trigger ADHD Symptoms in Teens? (HealthDay)

One crucial word here is symptoms, not diagnosis. The study tracked teenagers’ self-reports of 18 ADHD symptoms over a couple of years, crosschecking that with their self-reports of digital media use. That is not the same as tracking how many teens were diagnosed with ADHD. And it was based on what teens reported–self-reported information can be inaccurate and should be considered a study limitation.

Not surprisingly, reports of ADHD symptoms were slightly more common in the group of students who said they used digital media frequently. But not overwhelmingly so. And these are overall small numbers: Roughly 5 out of 51 students who reported using digital media a lot also reported ADHD symptoms, compared to about 22 of 495 students in the low-media use group.

The most important take-away here was that this study doesn’t show cause-and-effect, i.e., that smartphones trigger ADHD symptoms. It could be the other way around–that having a lot of ADHD-type behaviors triggers a lot of smartphone use.

While HealthDay’s headline jumped the shark and implied a cause-and-effect pattern, NBC News offered a more cautious take:

An independent source fleshes out an important caveat:

It is worth noting that over 80 percent of students reported high frequency use of digital media, and the vast majority of these students do not have elevated ADHD symptoms,” said Dr. Jessica Agnew-Blais, who researches psychology and neuroscience at King’s College London and who was not involved in the study.

Fortunately, all the stories we saw addressed at least some of the limitations. HealthDay, for example, pointed out the study did not look at parental influence on smartphone use and ADHD behaviors–which is undeniably a huge component that could sway the results.

It may be that parents of kids with a lot of ADHD symptoms permit more smartphone use simply to give themselves a breather, for example. Or it may be that parents who consistently strictly control their kids’ phone use also help their teens learn to control ADHD behaviors. And so on.

With observational studies like these, there are often more questions than answers. See our primer on this topic.

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Comments (2)

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Jennifer Newton

July 24, 2018 at 10:26 am

What a great synopsis to point out that the studies did not show cause and effect. Great analysis of limitations of observational studies (while still recognizing the salient points they bring up)

Jessica Parker

July 24, 2018 at 11:47 am

I recently read this study and had the same thoughts – this does not show cause and effect. There is such little information to state that digital media use causes ADHD.