New international review underscores growing health concerns over children's screen time

A comprehensive analysis of 121 studies reveals strong links between excessive screen use and mental health issues and obesity among young people, prompting calls for targeted public health responses.

A major review of international research is adding fresh weight to concerns about how much time children and teenagers spend on screens. The analysis, which pooled findings from 121 studies and was published in The Lancet as part of a wider series on children and digital media, suggests that excessive screen use is linked with a range of health problems, including mental health difficulties and weight gain. Researchers said the pattern is strong enough to merit public health attention, even though most of the studies reviewed cannot prove that screens directly caused the harm.

The review estimated that about one in five cases of depression and around 15% of cases of obesity among young people are associated with too much screen time. That does not mean the devices are the sole cause. Rather, the data point to a correlation that appears in many studies, including research in the International Journal of Obesity that found higher screen time was associated with a higher body mass index in adolescents. Taken together, the evidence suggests that prolonged use of phones, tablets and other digital devices may be part of a broader set of risks affecting young people’s physical and emotional wellbeing.

The effects are not the same for every child. The researchers said young people with existing mental health vulnerabilities, limited support away from the internet and lower digital literacy appear more likely to experience negative outcomes. They also noted that many studies relied on children reporting their own screen habits, which can make the evidence less precise. At the same time, the review stressed that digital media are not wholly harmful. They can help young people build independence, explore identity, find information, enjoy entertainment and maintain friendships, particularly when their use is intentional and guided by parents or carers.

Nicole Amoyal Pensak, a clinical psychologist who was not involved in the research, said teenagers are in a stage of both risk and opportunity because the brain is still rapidly developing. She urged adults to help children notice how different online activities affect their mood before, during and after use, and to pay attention to content that leaves them feeling worse. Pensak said parents should act as guides rather than simply gatekeepers, helping children identify which online experiences are useful and which are damaging. She suggested that active pursuits such as music, crafts, dance and practical tutorials may be especially helpful because they give young people something to do with their hands and attention, rather than encouraging passive scrolling.