Snapchat’s parent company has settled a civil lawsuit shortly before it was due to start in California, but other large tech companies still face a trial under the case.

Snap’s chief executive, Evan Spiegel, had been due to testify in a tech addiction lawsuit which also involves the Instagram owner, Meta; ByteDance’s TikTok; and Alphabet-owned YouTube – which have not settled.

Snap told the BBC the parties were “pleased to have been able to resolve this matter in an amicable manner”.

The Snapchat parent was among those being sued by a plaintiff named K.G.M, a 19-year-old woman who alleges that she developed mental health problems after becoming addicted to social media apps.

The California case is the first of three “bellwether” trials consolidating thousands of lawsuits. Last year a Los Angeles judge ruled that the platforms’ design features may be responsible for harm – and not just the third-party content posted on sites and apps.

Historically, tech firms have turned to section 230 of the Communications Decency Act, a law underpinning US internet regulation that exempts platforms from legal liability for content generated by its users, as part of their legal defence. The first bellwether case is still due to begin on 27 January with jury selection.

Snap remains a defendant in the other two cases.

Beasley Allen, a law firm involved in the lawsuits on the plaintiff side, has said the cases could have profound consequences including billions of dollars in damages, forcing changes in platform design and new US regulations governing how tech firms interact with minors.

“The litigation is being compared to past landmark cases against big tobacco and opioid manufacturers – industries that were held accountable for public health harms after years of denial,” the firm said in a statement last year.

Snap, Meta, TikTok and YouTube have been contacted for comment.