Though opiods are getting all of the government attention, and the substitute fentanyl all of the attention in media, they are not the only substances putting people at risk. Kratom has gotten some media attention, but among users, psilocybin-containing 'magic mushrooms' are a bigger worry, with more than 10 percent in a recent survey believing their worst 'bad trip' had put themselves or others in harm's way, and a substantial majority called their most distressing episode one of the top 10 biggest challenges of their lives.

According to the Substance Abuse and Mental Health Services Administration's National Survey on Drug Use and Health, about 22.9 million people or 8.7 percent of Americans, have reported use of psilocybin.

The survey results don't apply to all psilocybin mushroom use, since the questionnaire wasn't designed to assess "good trip" experiences, and it is unknown how often bad trips occur. Most of the respondents still reported the experience to be "meaningful" or "worthwhile," with half of these positive responses claiming it as one of the top most valuable experiences in their life.

Psilocybin and use of other hallucinogens became popular in the U.S. in the 1960s due to charismatic proponents, who suggested anecdotally that users would experience profound psychological insights and benefits. Drugs such as psilocybin and LSD were banned for safety reasons in the 1970s without much scientific evidence about risks.

More recently, some have insisted that psilocybin can treat psychological anxiety and depression and to aid in smoking cessation.

For the new survey, Griffiths' team used advertisements on social media platforms and email invitations to recruit people who self-reported a difficult or challenging experience while taking psilocybin mushrooms. The survey took about an hour to complete and included three questionnaires: the Hallucinogen Rating Scale, the Mystical Experience Questionnaire, developed by Griffiths and colleagues in 2006, and parts of the 5D-Altered States of Consciousness Questionnaire.

Participants were asked in the survey to focus only on their worst bad trip experience, and then to report about the dose of psilocybin they took, the environment in which the experience occurred, how long it lasted, and strategies available and used to stop this negative experience and any unwanted consequences.

Of 1,993 completed surveys, 78 percent of respondents were unsurprisingly men, 89 percent were also unsurprisingly white, and 51 percent had college or graduate degrees. 66 percent were from the U.S. On average, the survey participants were 30 years old at the time of the survey and 23 years old at the time of their bad trips, with 93 percent responding that they used psilocybin more than two times.

Based on the survey data that assessed each respondent's absolute worst bad trip, 10.7 percent of the respondents said they put themselves or others at risk for physical harm during their bad trip. Some 2.6 percent said they acted aggressively or violently, and 2.7 percent said they sought medical help. Five of the participants with self-reported pre-existing anxiety, depression or suicidal thoughts attempted suicide while on the drug during their worst bad trip, which the researchers say is indicative of requiring a supportive and safe environment during use, like those conditions used in ongoing research studies. However, six people reported that their suicidal thoughts disappeared after their experience on their worst bad trip -- the latter result coinciding with a recent study published by Griffiths showing the antidepressive properties of psilocybin in cancer patients.

Still, Roland Griffiths, Ph.D., a professor of psychiatry and behavioral sciences and neurosciences at the Johns Hopkins University School of Medicine, said, a third of the participants also said their experience was among the top five most meaningful, and a third ranked it in the top five most spiritually significant experiences of their lives. Sixty-two percent of participants said the experience was among the top 10 most difficult ones in their lifetime; 39 percent listed it in their top five most difficult experiences; and 11 percent listed it as their single most difficult experience.

"The counterintuitive finding that extremely difficult experiences can sometimes also be very meaningful experiences is consistent with what we see in our studies with psilocybin -- that resolution of a difficult experience, sometimes described as catharsis, often results in positive personal meaning or spiritual significance," Griffiths says. "Cultures that have long used psilocybin mushrooms for healing or religious purposes have recognized their potential dangers and have developed corresponding safeguards. They don't give the mushrooms to just anyone, anytime, without a contained setting and supportive, skillful monitoring."

The researchers say that survey studies like this one rely on self-reporting that cannot be objectively substantiated, and that additional scientifically rigorous studies are needed to better understand the risks and potential benefits of using hallucinogenic drugs.