[La Sagrada Familia] A priest, a rabbi, and a Zen Buddhist roshi walk into a bar and order a beer prestigious university lab to trip on psilocybin, the active ingredient in magic mushrooms. Wait, what? In recent weeks we've heard more and more about the resurgence in psychedelic research, with scientists from Johns Hopkins and New York University talking about how hallucinogenic psilocybin could work "like a surgical intervention for mental illness." But the big question of why psychedelic substances seem to have a profound and lasting impact — the ability to lift fear about the end of life, depression, and anxiety — is hard to answer. Among their most consistent effects is the hard-to-understand ability to reliably provide what researchers term "mystical," "spiritual," or "deeply profound" experiences (along with certain changes in brain activity that resemble those seen in people who meditate). But understanding what these experiences are and why they have such a significant effect isn't easy. So the same institutions that are working on showing that these drugs work in the first place are trying to figure out _why_ they work by turning to what might be considered some of the other experts in "mystical" or "spiritual" experiences, religious leaders from a variety of faith traditions. As a feature on this research by Shelby Hartman in Quartz reports, so far "they have enrolled thirteen religious leaders including an Orthodox Jewish rabbi, a Zen Buddhist roshi, an Episcopalian, a Greek Orthodox priest, and a Reform Christian for their FDA-approved clinical trial. (They’re also seeking Catholic priests, Imams, and Hindu priests to join the study.)" They hope that these volunteers can use their own spiritual experiences and vocabulary to try to better describe these psychedelic-induced experiences and to help figure out why they're so beneficial. "People emerge after the [psychedelic] experience reflecting back and believing that experience to be deeply personally meaningful to them," Roland Griffiths, a professor of psychiatry and behavioral sciences at JHU School of Medicine, told me when I recently wrote about how Johns Hopkins and NYU are testing psilocybin's ability to help patients deal with terminal illness. Griffiths says that he was initially skeptical about the power of hallucinogens before he began working with them, but was amazed by how in healthy volunteers who had never taken psychedelic drugs, these substances could reliably induce these moments that people often described as "one of the most significant spiritual experiences of their life." On a press call discussing those studies with ill patients, Griffiths explained that after taking psilocybin, people say they feel more "interconnected" with the world. "I think people after having had this experience are more accepting and more willing about engaging [with] life as it is," he explained. That seems to draw a link between these experiences and the reasons people might feel less depression or anxiety, but it still doesn't fully explain what those experiences mean and what their relationship is to other sorts of spiritual experiences, whether felt by someone in a church or by someone witnessing a sunrise on top of a mountain. In understanding that sort of thing, we're still at "very primitive levels," Griffiths told Business Insider. And perhaps drawing on the expertise of people who focus on spirituality might help. After all, traditionally things like psilocybin were the domain of the shaman, the person who intercedes between the divine and the human world. At the same time, it may be a help for those spiritual leaders too. Hartman writes that Anthony Bossis, who is in charge of the NYU religious leader trial, told her that some of these ministers began the trial having hit a certain level of burnout. But after their carefully monitored experience, similar to that of patients in other trials at NYU and Hopkins, many felt renewed. "They have increased passion for the scripture, for giving sermons, for helping people," Bossis told Quartz. "If that's sustained it will be remarkable." NOW WATCH: What magic mushrooms do to your brain and state of mind