A landmark series of papers published in The Lancet has shed new light on the health risks to young people from use of social media.

Researchers found just two hours a day of digital media use was linked to higher risk of harm for those aged under 25.

They called for “co-ordinated global action” to address the issue, urged tech companies to share data on how their platforms affected health, and said governments should step up regulation of features that may pose risks.

The research follows several major judgments against social media platforms in the US, and heightened scrutiny over how platforms safeguard their users.

It is likely to fuel further calls for major reforms in Britain, above and beyond the ban for under-16s set to come into force from March next year.

What did the research find?

The three-paper series, published here, comprises a major analysis of reviews covering nine million people under the age of 25.

It found excessive use of digital media – which researchers termed “problematic” – was linked to a higher risk of mental health problems, sleep issues and reduced exercise.

Researchers suggested more than two hours of screentime a day could be linked to around 2.8 million healthy years of life lost to depression, with 240,000 lost to obesity worldwide each year.

While the study stressed the links between “problematic” use and adverse outcomes was “modest”, experts said they were strong enough to justify urgent action.

The series chair, Professor Ilona Kickbusch, of the Digital Transformations for Health Lab (DTH-Lab) in Switzerland, said: “Use of digital media is now woven into the fabric of childhood and life as a young adult.

“Governments have let technology companies write their own rules, leading to business models built to capture attention and collect data, with health treated as an afterthought.

“The evidence linking problematic digital media use to poorer mental health, sleep and physical activity, although not conclusive, justifies co-ordinated, global action.”

Could platforms do more to minimise risk of harm?

The researchers were not satisfied by social media companies’ claims that they were proactively moving to address concerns about potential harm to users.

Professor Barbara Prainsack, of the University of Vienna, argued that platforms had adopted “a playbook well known from tobacco and fossil fuels: manufacture doubt, discredit critics, frame regulation as a threat to freedom”.

The University of Toronto’s Dr Jay Shaw said tech companies, not users or regulators, were responsible for how social media features were rolled out and presented.

“Most digital platforms are designed by companies to capture attention and collect data, not to protect health: features such as infinite scroll, autoplay and personalised recommendation feeds are deliberate design choices, not simply a matter of individual self-control,” he added.

Researchers suggested more than two hours of screentime a day could be linked to around 2.8 million healthy years of life lost to depression (Photo: Nicolas Tucat/AFP)

Beyond the design of features and safety measures, Louise Holly, of DTH-Lab UK, argued that platforms could help minimise future harm by increasing transparency.

“The most valuable data on how these platforms actually affect users are hidden within technology companies, limiting independent scrutiny and slowing scientific progress,” she said.

Her criticism reflects longstanding frustrations among politicians and activists, who have repeatedly accused tech companies of attempting to hide evidence that their platforms can cause harm.

How might study impact social media reform efforts?

The landmark study is likely to further increase scrutiny over the operations of social media companies.

A series of US lawsuits, primarily against Facebook and Instagram owner Meta, have sought to hold platforms accountable for addictive and potentially harmful features.

In a Los Angeles case earlier this year, Meta and YouTube were found liable for being deliberately addictive, although both have appealed against the ruling.

TikTok and Snapchat were named as defendants in the lawsuit, but settled before the trial began.

The plaintiff, known by her initials KGM, was awarded US$6m (£4.5m) in total damages by the jury, but the platforms were not required to make changes to their operations.

However, a ruling in August from a court in New Mexico did order Meta to alter its platforms, as well as to pay a $567m (£421m) fine to address harms to young people.

Meta was told to take steps including reining in addictive features, improving age verification and clamping down on child sexual exploitation.

The company has signalled it will appeal.

The study’s findings will add weight to the rulings, and will be likely to increase calls for additional regulations.

While Australia and the UK have pressed ahead with bans on social media for some young people, policy experts have highlighted complications in enforcing the measures, and instead argued governments must target specific features on platforms.

With the researchers flagging infinite scroll, autoplay and personalised recommendation feeds as potentially harmful, it is possible policymakers could introduce new laws aimed at limiting their impact on health.