Mobile phones should only be allowed from the age of 11, and internet access from 13. Social network access should only be granted from 15, and then only to networks deemed “ethical”.

The report urged that teenagers should be kept away from TikTok, Instagram and Snapchat until 18.

The experts pointed to social networks as a “risk factor” for depression or anxiety, in cases of “pre-existing vulnerability”. The amount of child exposure to pornographic and violent content “appears alarming”, they added.

“Cognitive bias is used to lock children on to their screens, control them, re-engage them and monetise them,” Mr Benyamina told Ouest-France.

“It’s an economy of capture. Parents are virtually out of the picture, faced with a market that has imposed itself on society,”  he added.

Young used social media to fuel riots

“What struck us is that the professionals’ priority is not the protection of children. Behind the rhetoric, it’s ‘business at every level’,” said Ms Mouton.

France has been locked in a heated debate over how to clamp down on bullying and suicides linked to teens’ use of social media. When riots erupted last July, President Macron warned that minors, who made up the bulk of rioters, were egging each other on via social networks.

Earlier this month, Gabriel Attal, the prime minister, called for a “surge of authority” to combat “the addiction of some of our teenagers to violence” after a 15-year-old was beaten to death outside his school in Viry-Chatillon.

“Attacking evil at its root also means regulating screens”, he said, describing social networks as “an accelerator of hatred” and a “catalyst of violence”.