The trial is set to determine whether Google and Meta deliberately designed their platforms to encourage compulsive use among young people, damaging their mental health in the process.

The case is expected to establish a standard for resolving thousands of lawsuits that blame social media for fueling an epidemic of depression, anxiety, eating disorders and suicide among young people.

TikTok and Snapchat, also named in the complaint, reached settlements with the plaintiff before the trial began.