Digital media has become inescapable, and there’s still a lot we don’t know about its effects on young people’s physical and mental health.
But we do have enough evidence of its harms to warrant government action, say the authors of a series on “digital determinants of health” published today in The Lancet.
The three-paper series and related meta-review, which analyzed existing research that included data from 9 million people younger than 25, were authored by experts from 10 different countries.
What the evidence says about digital harms
The study found consistent associations between problematic digital media use—meaning addiction-like patterns of use, rather than screen time alone—and various health outcomes.
Obesity, nearsightedness, lower back pain, and cardiometabolic risk were linked to overall screen time across different age groups.
Other findings differed by age. For children, higher overall screen time “was associated with poorer socio-emotional and cognitive development, increased anxiety and depression, and poorer sleep quality,” the review says.
For adolescents, specific patterns of digital engagement were associated with “reduced quality of life, sleep problems, lower physical activity, non-suicidal self-injury, suicidal ideation, and substance use.”
Overall, the meta-review said, “more than three-quarters of the reported exposure-outcome associations were adverse,” though there was also evidence of beneficial digital media use, like children watching educational content with caregivers, and adolescents using active video games.
“These age-related differences emphasize that digital media use is not a uniform phenomenon,” the meta-review said.
Roadblocks for research
Even with a large body of research to draw from, it’s difficult to quantify digital harms, and the authors stress that the available evidence doesn’t establish a cause-and-effect relationship between digital media use and specific health outcomes.
Self-reported data has limitations, said Sunny Xun Liu, director of research at the Stanford Social Media Lab.
Liu, who was not involved in the Lancet series, coauthored a recent study in JAMA Pediatrics that looked at how often adolescents reported negative online experiences, finding that responses varied substantially depending on the platform.
It can be hard to self-report media usage, Liu said. “If you ask [adolescents], ‘Okay, what type of harmful content have you seen in the past four weeks?’ it’s really hard for anybody to answer that question.”
Both Liu and the series authors said that better data does exist, but researchers often don’t have access to it.
“The most valuable data on how these platforms actually affect users are hidden within technology companies, limiting independent scrutiny and slowing scientific progress,” series author Louise Holly, a policy and research coordinator at the Digital Transformations for Health Lab in the U.K., said in a statement.
One of the series’ key recommendations is that governments should require tech companies to share that data with vetted public-interest researchers.
A public health approach to digital media regulation
Even in the absence of that data, the series authors say the scale of the evidence of digital harms is great enough that we should take action now.
They approach the topic from a public health perspective, and call for more research and more regulation, noting that single measures—like app age limits—aren’t enough.
“Technology companies are borrowing a playbook well known from tobacco and fossil fuels: Manufacture doubt, discredit critics, frame regulation as a threat to freedom,” series author Barbara Prainsack, a political science professor at the University of Vienna in Austria, said in a statement.
A public health approach that examines evidence across the whole population would counter that strategy, Prainsack said.
“Seen that way, good regulation isn’t the enemy of innovation—it’s a driver of good innovation, channeling it toward safety and trust,” she said. “And when regulation is missing, it doesn’t mean that a technology is ungoverned; it just means that companies set the rules instead of public policy.”
Liu agreed that the public health approach is important, and suggested several considerations for researchers and policymakers, recommending they “really listen to young people,” think about how to better support overwhelmed family and caregivers, and, lastly, that researchers look for novel ways to conduct their studies and make the complexities of digital media use easier to understand.