Due to the stigma of psychedelics, there has been a long gap in research, which may have started with 1962 "Good Friday Experiment" > Almost all of the members

Due to the stigma of psychedelics, there has been a long gap in research, which may have started with 1962 "Good Friday Experiment" > Almost all of the members of the experimental group reported experiencing profound religious experiences, providing empirical support for the notion that psychedelic drugs can facilitate religious experiences. One of the participants in the experiment was religious scholar Huston Smith, who would become an author of several textbooks on comparative religion. He later described his experience as "the most powerful cosmic homecoming I have ever experienced". https://en.wikipedia.org/wiki/Marsh_Chapel_Experiment https://en.wikipedia.org/wiki/Marsh_Chapel_Experiment