“Jurors found that Meta, which owns Instagram, Facebook and WhatsApp, and Google, owner of YouTube, intentionally built addictive social media platforms that harmed the 20-year old's mental health.”

“The woman, known as Kaley, was awarded $6m (£4.5m) in damages, a result likely to have implications for hundreds of similar cases now winding their way through US courts.”

“Meta and Google said they disagreed with the verdict and intended to appeal”

“Meta said: 'Teen mental health is profoundly complex and cannot be linked to a single app.'”

“Google said: 'This case misunderstands YouTube, which is a responsibly built streaming platform, not a social media site.'”

“The jury found that Kaley should receive $3m in compensatory damages and an additional $3m punitive damages, because they determined Meta and Google 'acted with malice, oppression, or fraud' in the way the companies operated their platforms.”

“Meta will be expected to shoulder 70% of Kaley's damages award, with Google the remaining 30%.”

“Parents of other children, who are not part of Kaley's lawsuit but claim they also were harmed by social media, were outside the courthouse on Wednesday, as they had been many days throughout the five-week trial.”

“The LA verdict came a day after a jury in New Mexico found Meta liable for the way in which its platforms endangered children and exposed them to sexually explicit material and contact with sexual predators.”

“Australia has imposed restrictions for children to stop or limit their use of social media. The UK is currently running a pilot programme to see how a ban of social media for people aged under 16 may work.”

“Kaley said she was 10 years old when she started having feelings of anxiety and depression, disorders for which she would be diagnosed years later by a therapist.”

“A separate case against Meta and other social media platforms over their alleged harms to children is poised to begin in June in California federal court.”

“Meta's growth goals were aimed at getting young people to use its platforms, Kaley's lawyers said.”

“Kaley said she started using Instagram aged nine and YouTube aged six, and encountered no attempts to block her because of her age.”

“Snap and TikTok were also initially defendants, but both companies reached undisclosed settlements with Kaley prior to trial.”

“Adam Mosseri, the head of Instagram, denied that 16 hours of daily use was evidence of an addiction.”

“Her lawyers argued that features of Instagram, like infinite scroll, were designed to be addictive.”

“Kaley has since been diagnosed with body dysmorphia, a condition which causes people to worry excessively about their physical appearance and prevents them from seeing themselves as others do.”

“Mark Zuckerberg, Meta's chairman and chief executive, relied on his company's longstanding policy of not allowing users under the age of 13 on any of its platforms.”