Does Excessive Screen Time Change Adolescents' Brains?

The increasing prevalence of screens and social media in the lives of children and adolescents have been a hot topic. There has been much public discussion and intense public debate about the ways that digital life has changed the experience of growing up, both in the United States and worldwide. And while it is clear to anyone who has watched a roomful of teenagers hunched silently over the phones that online life has drastically changed some aspects of adolescence, it is important to look at solid evidence of the implications of those changes when available. A new study published in PLOS Mental Health attempts to do just that.

Lead author Max Chang reviewed a dozen articles that used fMRI to observe the brains of adolescents between the ages of 10-19 who had been clinically diagnosed with Internet addiction (although it is not a DSM-5 diagnosis). The criteria for Internet addiction involve an inability to resist the urge to go online to the point where it negatively affects a person's day-to-day functioning. Often, people with Internet addiction find their professional or academic lives, their moods, and their relationships impaired because of their excessive use.

The studies, all of which had been conducted over the past 10 years, included a total of 237 adolescents with Internet addiction and noted changes in how different parts of the brain connect with each other, observing participants both while resting and also completing a task. This brain connectivity is referred to as functional connectivity and can tell us a lot about the overall way that a person's brain behaves. The study showed that generally, adolescents with Internet addiction showed less functional connectivity in the executive network areas of the brain, the parts that are most involved with active thinking. This suggests that Internet addiction is associated with brain changes that might affect, according to the study, cognitive control, reward valuation, and motor coordination.

With many parents overwhelmed by the hand-wringing over screen use in their children, might it change things to have more concrete physiological data such as this research? Would it be helpful for parents to think of screen use—and screen use to the point of compulsive behavior and addiction—as something that has physiological effects that can actually be measured? Though many parents know of the hypothetical dangers of extreme amounts of screen use, these dangers often seem more abstract and vague. Just as many people have a harder time understanding psychological effects than they do concrete physical effects. If excessive screen use were to be shown to have tangible effects on the developing brain in the manner that smoking cigarettes has effects on the lungs, perhaps it would give parents a clearer way to conceptualize what they are up against.

Nonetheless, this study has limitations. Most participants came from Asian countries, and the sample size was small. Further research could be crucial in continuing to delineate and make sense of these effects and apply them to a broader group of adolescents, perhaps helping parents understand how it applies to their own families as they struggle to make decisions regarding one of the most controversial and divisive child-rearing topics of our time.