This research paper describes a major clinical trial testing whether psilocybin (the active compound in magic mushrooms) can treat depression that doesn’t respond to standard medications. The trial involves 144 patients receiving either psilocybin at different doses or a placebo in a carefully controlled medical setting with psychological support. The researchers developed special methods to address unique challenges in psychedelic research, such as making it difficult for patients to guess whether they received the active drug, and ensuring all patients eventually get access to the potentially helpful treatment.