The company hid findings that use of its social media platform was linked to depression and anxiety, documents allegedly show

Facebook's parent company Meta hid the results of in-house research into the negative health impacts of using the social media site, according to recently unredacted court filings.

The company's internal communications were released on Friday as part of a long-running, high-profile lawsuit brought by US school districts against several social media firms. It alleges that their platforms have caused mental harm and addiction among children and teenagers.

In a 2020 research study, Meta asked people to stop using Facebook for a period of time, comparing them to a control group that continued normal use, according to the documents.

"To Meta's disappointment, pilot tests of the deactivation study confirmed that 'people who stopped using Facebook for a week reported lower feelings of depression, anxiety, loneliness, and social comparison'," the filings allege.

Despite their own findings about the causal link between Facebook use and adverse mental health effects, "Meta lied to Congress about what it knew," the filings allege.

The social media giant has faced increased scrutiny in the US in recent months.

In October, Meta said it would add new safeguards to its "teen accounts," allowing parents to turn off their children's communications with the company's AI chatbots, following earlier revelations that they could engage minors in romantic or sensual conversation.

The company has also faced pressure from the US Federal Trade Commission, which has accused it of holding a monopoly in social networking.

However, last week a Washington district court ruled in Meta's favor in the antitrust lawsuit, stating that the US competition watchdog had not proven that the company currently holds a monopoly, "whether or not Meta enjoyed monopoly power in the past."