The dose levels of the "sacred mushroom" chemical capable of yielding positive, life-changing experiences have been examined by scientists at the Johns Hopkins University School of Medicine.
At the same time, they have also focused on while minimizing the chance of transient negative reactions in screened volunteers under supportive, carefully monitored conditions.
The findings, published online this week in the journal
Psychopharmacology, come from the latest in a series of rigorous experiments done at Johns Hopkins designed to shed scientific light on psilocybin, a substance found in certain psychoactive mushrooms and used for centuries in various cultures for divinatory, healing, and religious purposes.
Looking back over a year later, most of the experiment''s 18 volunteers (94 percent) rated a psilocybin session as among the top five most or as the topmost spiritually significant experience of his or her life. Under higher doses, up to a third experienced great fear or anxiety or had delusions, yet those reactions, the researchers report, were managed with gentle reassurance from the study monitors and did not outlast the session or harm the volunteers.
Most volunteers (89 percent) also reported positive changes in their behaviors, and those reports were corroborated by family members or others, the researchers say. The behavior changes most frequently cited were improved relationships with family and others, increased physical and psychological self-care, and increased devotion to spiritual practice.
In the experiment, volunteers were given preparatory guidance and five sessions each a month apart, four with different doses of psilocybin and one with placebo (no dose). While the positive effects of psilocybin increased with increasing doses, the likelihood of fear or delusions increased sharply at the highest doses. At the second-highest dose given, two-thirds of the volunteers rated the experience as among the five most spiritually significant of their lifetime, and just 5.6 percent reported intervals of "extreme" fear or anxiety during the session. With the highest dose, the percentage of participants having a top-five experience rose modestly, from 67 percent to 78 percent, but the percentage of those having psychological struggle rose sixfold, to 33 percent.