It’s no longer controversial to suggest that humans and their smartphones aren’t always a healthy combination. Strong research has been coming in over the last several years, suggesting that looking at screens for hours a day can have some serious health and mental health consequences. Even some of the developers of these products have admitted guilt about their creations, and confessed that they don’t even let their kids use them. A couple of recent studies highlight the connection, and an infographic below expands on it.
One new study finds that time spent on screens is linked to not-so-great shifts in brain connectivity, while reading is linked to more beneficial changes. The researchers, from Cincinnati Children’s Hospital, had families rate how much time their kids spent on screens (smartphones, tablets, computers, and TV) and how much time they spent reading actual books. The children’s brains were scanned, to assess how regions involved in language were connected, and it turned out that screen time was linked to poorer connectivity in areas that govern language and cognitive control. Reading, on the other hand, was linked to better connectivity in these regions.
Another recent study found that the brain chemistry of kids who fell into the category of smartphone or Internet addiction was different from that of non-addicted kids. In particular, changes were seen in the reward circuits of the brain, in the ratio of the neurotransmitter GABA to other neurotransmitters. (Interestingly, these changes generally reversed when the teens went through cognitive behavior therapy (CBT) for their addiction.) And other research has reported that cells in one of the reward areas of the brain, the nucleus accumbens, are activated when participants view Instagram pictures with more “likes," which again suggests that social media use can tap into addiction pathways.
But what may be even more important than looking at the brain is looking at the behavior and the psychology of kids who use screens. Researcher Jean Twenge’s famous work has shown strong links between time spent on screens and depression and suicidality in teens. A recent study of hers reported that teens who spent more time on screens in the form of social media, internet, texting, and gaming thought about suicide a lot more than kids who didn’t: about 48% of those who spent five or more hours a day on their phones had thought about suicide or made plans for it, while 28% of the teens who spent only one hour per day on their phones. In fact, teens who spent more time doing sports, homework, socializing with friends in real life, and going to church had a lower risk for both depression and suicide.
"These increases in mental health issues among teens are very alarming,” said Twenge, who’s also the author of iGen: Why Today’s Super-Connected Kids Are Growing Up Less Rebellious, More Tolerant, Less Happy--and Completely Unprepared for Adulthood--and What That Means for the Rest of Us, in a statement. “Teens are telling us they are struggling, and we need to take that very seriously."
It can be tricky to tease apart the effects of screens on mental and physical health, but researchers are doing remarkably well. Below are some more of the effects that too much screen time seems to have on the developing body and brain.