Since 1962 scientists have been giving psilocybin to volunteers and asking whether what follows is religious. Here is what they measured, what they found, and what they cannot tell us, read by people who keep the rite. It is a summary of published studies, not medical advice and not an invitation.
The researchers did not invent their definition. They borrowed it from philosophers of religion, who took it from the mystics.
William James named four marks in 1902: it cannot be put into words, it feels like knowledge, it passes, and it happens to you rather than being done. The philosopher Walter Stace refined the list in 1960 from the writings of mystics across many faiths, and every questionnaire the laboratories use today is built on his.
The sense that all is one: either the world seen as a single living whole, or the self dissolving into something without parts. Stace thought the second the deeper of the two.
Reverence and awe; the sense of standing in the presence of something holy.
Knowing. The conviction of having met something more real than everyday reality, which does not fade when the experience does.
Joy, peace, tenderness, and a love that people often describe as unconditional.
Losing the ordinary sense of when and where you are; the feeling of being outside time altogether.
The difficulty, often the impossibility, of putting it into words afterward.
The sense that contradictory things were both true: empty and full, nothing and everything, dying and more alive than ever.
Visions, voices, and meetings with gods, spirits or the dead are deliberately left out of the scientific definition; so are a purely beautiful experience and a purely psychological insight. A pagan reading the questionnaire notices at once that there is no box for the goddess. Jay Michaelson, a rabbi and meditation teacher who studies psychedelics and religion at Emory, makes the same point: the standard measure often misses what practitioners care about most, the beings, the ancestors, the spirits of nature, the healing of old wounds. Keep that in mind when you read the numbers below.
A complete mystical experience, in these studies, means scoring at least sixty per cent of the maximum on every part of the questionnaire. It is a high bar, and it is the number most often reported.
The figures below come from the published papers, chiefly as summarised by Frederick Barrett and Roland Griffiths of Johns Hopkins in their 2018 review of the field.
At Boston University's Marsh Chapel, Walter Pahnke gave twenty Protestant divinity students either 30 milligrams of psilocybin or nicotinic acid, a vitamin that flushes the skin and was meant to fool them. By his strict standard, three or four of the ten who took psilocybin had a complete mystical experience; none of the others did. When Rick Doblin found sixteen of the twenty a quarter of a century later, the psilocybin group described the day in almost the same words and still credited it with lasting change. Doblin also reported what the original write-up had left out: the blind broke soon after the doses were given, and one participant became so agitated that he was given a tranquillising injection.
Roland Griffiths and colleagues gave thirty-six healthy adults who had never taken a psychedelic a high dose of psilocybin in one session and an active placebo, the stimulant methylphenidate, in another: alone, with two trained sitters, in a room furnished like a living room, with music and eyeshades. On psilocybin, 61 per cent had a complete mystical experience; on the placebo, 11 per cent. Two months later a third called it the single most spiritually significant experience of their lives. Fourteen months later, two-thirds still placed it in their top five, and friends and family, asked separately, reported small but real changes for the better.
The same group gave volunteers four doses of psilocybin and a placebo, months apart. The higher the dose, the more often a mystical experience, and the more often lasting change in attitude and behaviour: at the two highest doses, 72 per cent had a complete mystical experience and 83 per cent counted a session among the five most spiritually significant experiences of their lives. A related analysis found that the personality trait of openness rose in those who had a complete mystical experience, and stayed raised.
In Basel, volunteers took a high dose of LSD in a standard hospital room with optional music. It produced the highest mystical scores of any drug in the study, and yet only one in eight had a complete mystical experience. Pooling their own high-dose sessions, where 57 per cent did, the Hopkins authors credited the difference mainly to "greater volunteer preparation before and support during the sessions."
Fifteen smokers took psilocybin alongside a course of therapy; six months later, twelve had not smoked, confirmed by tests. Ten people dependent on alcohol drank significantly less after two sessions. Fifty-one people with life-threatening cancer had large falls in anxiety and depression. In each study, the strength of the mystical experience tracked the size of the benefit. The groups were small and some had no placebo; these are promising first steps, not proof.
Researchers in Natal and Sao Paulo, testing ayahuasca for depression, found that a single dose could bring rapid relief. As the religious-studies scholar Larissa Carneiro tells it, early efforts to strip the brew down to one molecule, to spare people the nausea, did not work; the trials did better once the laboratory looked more like a church service, with soft light, a reclining chair and hymns in the background, and with the brew supplied by the ayahuasca churches themselves.
The classic psychedelics, psilocybin, LSD, mescaline and DMT, all act on the brain's serotonin 2A receptors, which are dense in the regions most involved in our sense of self. That is roughly where the agreement ends.
The most discussed finding concerns the default mode network, a set of brain regions first described in 2001 that is busiest when we are at rest: daydreaming, remembering, imagining the future, thinking about ourselves. During a psychedelic experience, activity and communication within that network tend to fall, and the more they fall, the more people report their sense of self dissolving. Other researchers point to the thalamus, the relay that filters what the senses send upward, and suggest that psychedelics open the gate wider; others to the claustrum, a thin sheet of neurons that may help bind experience together.
Every one of these ideas has problems. Alcohol also changes the default mode network and produces nothing like a mystical experience. Studies using different scanners and different routes of dosing have found the same regions going up and going down. Experienced meditators show some of the same quietening without any drug. The Hopkins authors themselves write that psilocybin is "neither necessary nor sufficient" for a mystical experience, and that whether such an experience can be reduced to brain activity at all remains an open question.
Some members find the neuroscience a gift: a naturalist's account of what the mystics described. Others find it beside the point, a map of the road that says nothing about the city. Both are welcome in circle.
What matters to the fellowship is the finding underneath. The experience depends on the brain, the brain depends on the setting, and the setting is ours to keep.
Meditation, prayer, breathwork, deep listening to music, sensory deprivation: the Hopkins review lists all of them as documented routes to the same experience. That is the scientific case for sober practice.
The researchers are candid about most of this. The press releases often are not.
Healthy, carefully screened, mostly well-educated volunteers with no personal or family history of psychosis. The results say nothing about the people the screening turned away. Our Safety page follows the screening, not the headlines.
Dozens, not thousands. Several of the clinical studies had no placebo group at all. "Promising" is the honest word, and it is the one the better researchers use.
It is very hard to hide from someone that they have taken a psychedelic, and expectation shapes the experience. The researchers control for it as best they can. Nobody has eliminated it.
The questionnaire was refined by the same group that relies on it, has no outside standard to check it against, and was built for one kind of experience. It has no box for the goddess, the ancestors or the spirit of the place.
Not every experience is mystical. Some loss of self is terrifying and joyless, and can leave lasting distress. Studies report averages; the warden sits with one person.
Science can show that people have these experiences, what predicts them and what follows. It cannot tell you whether the unity you felt was real. That question belongs to the circle, the tradition, and you.
We did not need a laboratory to tell us how to keep a rite. We are glad of the evidence all the same.
The same class of molecule produced complete mystical experiences in more than half of prepared volunteers in a quiet, warded room, and in one in eight in a plain hospital room. Preparation, support and a room that feels safe are not decoration. They are the rite. See Set, setting and the cast circle.
The researchers and the mystics agree: the experience comes through meditation, prayer, breath, music and fasting too, and the sacrament does not guarantee it. Most of our rites are sober because most of the road always was.
What predicted lasting change was not how strong the drug effect was but whether the experience had the qualities of the mystical, and what people did with it afterward. That is why our rule is less, not more, and why every rite ends in integration.
Questionnaires are tools for researchers. In circle, nobody's night is measured against anyone else's, and an evening of nothing but tears, sleep or stars is a rite completed.
Read who should not journey before you read anything else about journeying.