A new series of papers in The Lancet examined 2,790 studies that together included more than nine million participants, looking at how digital devices affect children and young adults.

The review found that children under 10 who use screens excessively tend to sleep less and show slower development in thinking, emotions and social skills.

For people aged 10 to 24, heavy screen use is linked to mental‑health issues, lower physical activity, substance abuse, self‑harm and thoughts of suicide.

Co‑author Jay Shaw, an assistant professor in the University of Toronto’s Department of Physical Therapy, says the real scale of the problem cannot be measured without access to user data held by tech companies.

Shaw and his fellow researchers argue that screen addiction should be treated as a public‑health issue, comparing the need for action to the historic fight against tobacco.

They call on governments to step in, just as they did with smoking, and suggest legislation like Canada’s proposed Safe Social Media Act could force platforms to share data and protect young users.