A day after the regulatory rejection of Lykos Therapeutics’ MDMA-assisted therapy for PTSD, the scientific community faced another setback as a prominent medical journal retracted three significant studies on the same subject. On Saturday, the journal Psychopharmacology formally pulled three papers that investigated the use of MDMA, a psychoactive drug, for treating post-traumatic stress disorder (PTSD).

The retraction was prompted by serious ethical concerns. According to Psychopharmacology, the studies were marred by “protocol violations amounting to unethical conduct” at one of the research sites. The retraction notice revealed that the study authors were aware of these breaches at the time of submitting their manuscripts but chose not to disclose this critical information to the journal. Moreover, the authors failed to exclude the compromised data from their analyses, further undermining the integrity of the findings.

In addition to these ethical lapses, the retraction notice highlighted issues of undisclosed conflicts of interest. Some of the researchers involved were linked to the Multidisciplinary Association for Psychedelic Studies (MAPS) or its subsidiaries, which not only funded the studies but also supplied the MDMA used. This connection was not fully disclosed by many of the authors, raising concerns about potential bias.

One of the study’s authors, Allison Feduccia, agreed with the retraction but took issue with the language used by the journal in its official notice. Speaking with STAT News, Feduccia explained that her agreement to the retraction was driven by Psychopharmacology‘s refusal to allow the authors to amend the data, rather than any fundamental disagreement with the need to retract. However, other key figures in the studies, such as Michael Mithoefer, Lisa Jerome, Berra Yazar-Klosinski, and Rick Doblin, voiced their opposition to the retraction. The remaining authors did not respond to the journal’s request for comment.

This retraction added further challenges to the controversial MDMA-assisted therapy for PTSD, coming just a day after the U.S. Food and Drug Administration (FDA) rejected Lykos Therapeutics’ application for its MDMA-assisted PTSD treatment. The FDA’s decision, outlined in a Complete Response Letter, stated that the data Lykos provided was insufficient for approval and called for an additional Phase III clinical trial. Lykos has indicated its intention to request a meeting with the FDA to discuss the decision and seek guidance on resubmission.

The FDA’s rejection was consistent with the views expressed by its Psychopharmacologic Drugs Advisory Committee. In June 2024, the committee voted 10-1 against Lykos, citing concerns over selection bias and potential unblinding in the Phase III trial presented by Lykos. The committee also raised alarms about possible misconduct and manipulation of trial results. Kim Witczak, the consumer representative who voted against Lykos, emphasized these concerns, noting the troubling potential for trial manipulation.

Compounding the controversy, a report from the Institute for Clinical and Economic Review (ICER) in May 2024 had already criticized Lykos’ MDMA-assisted therapy. The ICER report questioned the trial’s patient enrollment practices, suggesting that participants were drawn disproportionately from communities with a strong pre-existing interest in psychedelic therapies. The report also noted that some therapists and patients involved had “very strong prior beliefs” about MDMA, which could have influenced the study outcomes. Additionally, the report alleged that there had been “pressures” to produce favorable results, further clouding the credibility of the trial’s findings.

Together, these developments cast a long shadow over the potential future of MDMA-assisted therapy for PTSD, raising critical questions about research integrity, regulatory oversight, and the ethical dimensions of psychedelic-assisted treatments.