People who took an illegal drug made from mushrooms reported profound mystical experiences that led to behavior changes lasting for weeks -- all part of an experiment that recalls the psychedelic '60s.
Many of the 36 volunteers rated their reaction to a single dose of the drug, called psilocybin, as one of the most meaningful or spiritually significant experiences of their lives. Some compared it to the birth of a child or the death of a parent.
Such comments "just seemed unbelievable," said Roland Griffiths of the Johns Hopkins University School of Medicine in Baltimore, Maryland, the study's lead author.
But don't try this at home, he warned. "Absolutely don't."
Almost a third of the research participants found the drug experience frightening even in the very controlled setting. That suggests people experimenting with the illicit drug on their own could be harmed, Griffiths said.
Viewed by some as a landmark, the study is one of the few rigorous looks in the past 40 years at a hallucinogen's effects. The researchers suggest the drug someday may help drug addicts kick their habit or aid terminally ill patients struggling with anxiety and depression.
It may also provide a way to study what happens in the brain during intense spiritual experiences, the scientists said.
Funded in part by the federal government, the research was published online Tuesday by the journal Psychopharmacology.
Psilocybin has been used for centuries in religious practices, and its ability to produce a mystical experience is no surprise. But the new work demonstrates it more clearly than before, Griffiths said.
Even two months after taking the drug, pronounced SILL-oh-SY-bin, most of the volunteers said the experience had changed them in beneficial ways, such as making them more compassionate, loving, optimistic and patient. Family members and friends said they noticed a difference, too.
Charles Schuster, a professor of psychiatry and behavioral neuroscience at Wayne State University in Detroit, Michigan, and a former director of the National Institute on Drug Abuse, called the work a landmark.
"I believe this is one of the most rigorously well-controlled studies ever done" to evaluate psilocybin or similar substances for their potential to increase self-awareness and a sense of spirituality, he said. He did not participate in the research.
Psilocybin, like LSD or mescaline, is one of a class of drugs called hallucinogens or psychedelics. While they have been studied by scientists in the past, research was largely shut down after widespread recreational abuse of the drugs during the 1960s, Griffiths said. Some work resumed in the 1990s.
"We've lost 40 years of (potential) research experience with this whole class of compounds," he said. Now, with modern-day scientific methods, "I think it's time to pick up this research field."
The study volunteers had an average age of 46, had never used hallucinogens, and participated to some degree in religious or spiritual activities such as prayer, meditation, discussion groups or religious services. Each tried psilocybin during one visit to the lab and the stimulant methylphenidate (better known as Ritalin) on one or two other visits. Only six of the volunteers knew when they were getting psilocybin.
Each visit lasted eight hours. The volunteers lay on a couch in a living-room-like setting, wearing an eye mask and listening to classical music. They were encouraged to focus their attention inward.
Psilocybin's effects lasted for up to six hours, Griffiths said. Twenty-two of the 36 volunteers reported having a "complete" mystical experience, compared with four of those getting methylphenidate.
That experience included such things as a sense of pure awareness and a merging with ultimate reality, a transcendence of time and space, a feeling of sacredness or awe, and deeply felt positive mood like joy, peace and love. People say "they can't possibly put it into words," Griffiths said.
Two months later, 24 of the participants filled out a questionnaire. Two-thirds called their reaction to psilocybin one of the five top most meaningful experiences of their lives. On another measure, one-third called it the most spiritually significant experience of their lives, with another 40 percent ranking it in the top five.
About 80 percent said that because of the psilocybin experience, they still had a sense of well-being or life satisfaction that was raised either "moderately" or "very much."