A key study reviewed by the FDA to determine whether ecstasy should be approved for medical use was rife with flaws and bias, the Wall Street Journal reported Monday. Among the study’s reported issues was a pressure campaign in which at least three subjects with post-traumatic stress disorder said they felt they had to report positive outcomes because it’d “lead to a history-making drug approval.” In reality, however, those subjects told the Journal that ecstasy, a psychedelic also known as MDMA, led to their thoughts of suicide worsening during or after testing. Those suicidal thoughts reportedly weren’t captured in trial data and did not make it into the study’s final results—potentially corrupting the FDA’s view of the drug’s effectiveness on an already-vulnerable population. The leader of the study, Lykos Therapeutics, disputed the report and said the study was “sound” and that its “data is reliable.” The approval of ecstasy would be a major milestone after decades of efforts to decriminalize psychedelics. The FDA is expected to make its determination on ecstasy as early as this week, the Journal reported.