“Magic” mushrooms really do have a spiritual effect on people, according to the most rigorous look yet at this aspect of the fungus’s active ingredient.

About one-third of volunteers in the carefully controlled new study had a “complete” mystical experience after taking psilocybin, with half of them describing their encounter as the single most spiritually significant experience in their lifetimes.

However, psilocybin use has been associated with side effects such as severe paranoia, nervousness and unwanted flashbacks and so experts warn against experimentation. “Once you’ve started down the path, you might not like where it ends,” comments Herbert Kleber, a psychiatrist at Columbia University in New York, US. “These are powerful agents that are just as likely to do harm as to do good.”

Psilocybin is found in mushrooms such as the liberty cap (Psilocybe semilanceata and about 186 other species. Hippies embraced the compound during the 1960s, after its mind-altering potential was touted by Timothy Leary, then a researcher at Harvard University in Cambridge, Massachusetts. But as its use grew, US lawmakers took action. It is now generally illegal to sell or possess psilocybin drugs in the US.


Demonised compound

But Roland Griffiths, of Johns Hopkins University School of Medicine in Baltimore, Maryland, US, and his colleagues believe there is a need to revisit the biological effects of psilocybin, which have been virtually ignored by the scientific community for about 40 years. “It so traumatised our society that we’ve demonised this compound,” he says.

Griffiths’s team recruited 36 healthy volunteers who had not experimented with the drug before. They were informed that they would receive a hallucinogen but did not know in which of two or three sessions they would receive it. Each session was separated by two months.

They either received a substantial dose – about 30 milligrams – of psilocybin or a similar dose of an “active” placebo, Ritalin. The latter has a stimulating effect but is not known as a hallucinogen. An inactive placebo would be easy to identify by the volunteers when compared to psilocybin, which could bias the experiences they reported.

The researchers used psychological questionnaires and found that 22 of the 36 volunteers had a “complete” mystical experience after taking psilocybin – far more than the four who reported this type of experience after taking Ritalin.

More than one-third of the volunteers said that their encounter with psilocybin was the single most spiritually significant experience in their lifetimes – no person given Ritalin said the same. Experts say the study is the most rigorous study of psilocybin’s potential to elicit spiritual feelings because it is the first to use an active control.

Spiritual shortcut

However, more than 20% of the participants described their psilocybin sessions as dominated by negative feelings such as anxiety. And while psilocybin appears to mimic the brain signalling-chemical serotonin, its precise action on mind function remains elusive.

Griffiths says that in the future psilocybin might have a therapeutic use, perhaps helping people who have just learned they have cancer come to terms with the news. But he is quick to add that “the therapeutic application is very speculative”.

“My guess is that there will be people saying You’re looking for a spiritual shortcut'” says Griffiths. He stresses that the drug is no replacement for the mental health benefits of continuous personal reflection: “There’s all the difference in the world between a spiritual experience and a spiritual life.”

Journal reference: Psychopharmacology (DOI: 10.1007/s00213-006-0457-5)