Unredacted lawsuit claims Meta shut down study that found a week off its apps improved mental health

Meta is accused of suppressing internal research that indicated users’ mental health improved after stepping away from Facebook and Instagram for one week, according to allegations in an unredacted court filing tied to a class action brought by U.S. school districts against Meta, Google, TikTok and Snapchat.

The filing centers on “Project Mercury,” internal research conducted about half a decade ago. The documents allege Meta halted the project after it found causal evidence that its products harmed users’ mental health. People who stopped using Facebook and Instagram for one week reported lower feelings of depression, anxiety, loneliness and social comparison, the filing says.

Rather than publish the results or pursue further study, the company ended the work, internally arguing the findings were tainted by media narratives about social media harms, according to the documents. The filing also says staff responsible for the research told company leadership there was a causal impact on social comparison, and one employee likened Meta’s actions to the tobacco industry’s concealment of health risks.

If accurate, the materials would contradict Meta’s prior statements to Congress that it lacked the ability to quantify whether its products harmed teenage girls, the filing contends. Additional allegations in the internal documents include claims that youth safety features were designed to be ineffective and rarely used, and that the company blocked tests on features feared internally to be harmful to growth.

The filing further alleges Meta maintained a high strike threshold, requiring users to be caught 17 times attempting to traffic people for sex before they were removed from the platform. According to the allegations, Meta also found it could increase teen engagement by serving more harmful content and proceeded for the sake of revenues.

The documents claim that in 2021 CEO Mark Zuckerberg said child safety was not his top concern, prioritized building the metaverse and rejected requests to increase funding for child safety work. Meta disputes the accusations. Company spokesman Andy Stone said Meta strongly disagrees with the filing’s characterizations, calling them cherry-picked quotes and misinformed opinions.

He said Project Mercury was shut down because of flawed methodology and that the company’s teen safety measures are effective. Stone also said Meta’s current policy is to remove sex-trafficking accounts as soon as they are flagged. A court hearing on the filing is scheduled for January 26, 2026, in Northern California District Court.

Meta has filed a motion to strike the internal documents cited in the case.