Screens, children and mental health: it's not just a question of timers

Screens are not all the same and time is not the only variable to be controlled. A new study by researchers at Columbia's Vagelos College of Physicians and Surgeons and Weill Cornell Medicine suggests that children's use of social media, video games or mobile phones in relation to mental health should be better studied. In short, it is not the total time spent in front of the screen that makes them more or less addicted, it is no longer just a question of dosage. What was published on Wednesday in the Journal of the American Medical Association (Jama) is not 'the new law of relativity' of 'addictions' to social, smartphones and video games, but a study that for the first time tries to focus on the long-term effect of digital technologies, particularly for children whose brains are still developing and at a time when they are surrounded by screens.

To date, most research has focused on the total time spent in front of the screen, rather than on the nature of the time spent in front of the screen or how this usage may change over time. Instead, the study examined the social media use of nearly 4,300 children, starting at the age of eight, and how usage changed over the next four years. As the researchers explained, excessive screen use that is addictive, i.e. that interferes with schoolwork, behaviour at home or other activities, should be analysed. The central novelty is not so much in linking screens and anxiety or depressed mood - this had already emerged in previous research - but in focusing on patterns of compulsive use. For mobile phones, about half of the children reported high addictive use from the beginning of the study, which remained high until early adolescence, and about 25 per cent developed increasingly addictive use as they got older. As for social media, about 40% of the children had high or increasingly addictive use. Unlike social media and mobile phones, video game use followed only two trajectories, high and low, with no distinct 'increasing' group over time.

Teenagers with increasing or intensely compulsive use showed a 2-3 times higher risk of thinking about or attempting suicide, as well as developing anxiety, depression, agitation or disruptive behaviour. "For parents and educators, the discussion about mobile phones and social media has focused on limiting or banning use, but our results indicate that more complex factors are involved," said first author Dr. Yunyu Xiao, first and lead author, assistant professor of population health sciences and psychiatry at Weill Cornell Medicine. "Clinical studies have shown that restricting mobile phone use, such as during school hours, was not effective in reducing the risk of suicidal behaviour or improving other aspects of mental health." As if to say, it is not only bans and timers that will help us understand and deal with this type of addiction.

As Lisa Henderson, head of the Department of Psychology at York University explained in the Financial Times, "a we also need to determine the neurobiological and psychological mechanisms that underlie the relationships between addiction use and mental health outcomes". "For example . he continued - converging evidence suggests that sleep disturbances may be a mediating mechanism here".