Meta Allegedly Buried Research Linking Facebook Use To Mental Harm

Unredacted court filings made public on November 23 allege that Meta halted an internal research project in 2020, code named Project Mercury, after findings indicated that users who deactivated Facebook for one week reported reduced feelings of depression, anxiety, loneliness and social comparison. The filings, disclosed in a Reuters report, say Meta and external researchers from Nielsen interpreted the results as evidence of causal harm, and that internal communications described a causal link between Facebook use and negative social comparison.

Plaintiffs in the suit are a coalition of U.S. school districts that contend social platforms contribute to mental health harms among students. The filings were produced through discovery in broader litigation that names multiple companies, and a court has scheduled a hearing in January 2026 to consider unsealing additional documents. The disclosures add to an array of legal and regulatory challenges facing Meta and other technology firms over youth safety and platform accountability.

According to the filings, rather than expand or publish the Project Mercury work, Meta stopped the research and internally characterized the findings as being tainted by external media narratives. The plaintiffs also accuse the company of designing youth safety features that were ineffective, of stalling or blocking safety testing when those tests might have reduced user engagement, and of deprioritizing safety work that could have hurt growth metrics.

Meta has responded to the allegations, denying that it suppressed valid findings. Company representatives told Reuters that the study’s methodology was flawed and emphasized that Meta remains committed to improving safety across its products. The filings show the simmering tension between business incentives tied to engagement and the mounting evidence, from both internal and external studies, that prolonged social media use can affect adolescents’ mental health.

The Project Mercury revelations arrive in a climate of heightened concern about the effects of social media on young people. Lawmakers, regulators and public health experts have pressed platforms for greater transparency and for product designs that reduce harm. The newly surfaced filings could influence pending litigation and inform legislative efforts aimed at platform accountability, as courts weigh how much of companies’ internal research should be available in public records.

Legal experts say the January hearing will be pivotal in determining whether more internal documents become public and how those documents can be used in ongoing suits. If the filings lead to more disclosures, they could provide researchers and policymakers with rare windows into the internal trade offs technology companies make between safety investments and user growth.

For parents, educators and policymakers, the allegations underscore an urgent question about the responsibilities of platforms that reach millions of adolescents. Whether the court unseals additional materials later this winter, the claims in the current filings are likely to intensify debates about how to align product design, public health evidence and corporate incentives in the age of ubiquitous social media.