Young adults ages 19 to 30 nearly doubled their past 12-month use of non-LSD hallucinogens in the United States from 2018 to 2021, according to a study by the University of Michigan and Columbia University.

In 2018, the prevalence of young adults’ past-year use of non-LSD hallucinogens was 3.4%. In 2021, that use increased to 6.6%.

“While non-LSD hallucinogen use remains substantially less prevalent than use of substances such as alcohol and cannabis, a doubling of prevalence in just three years is a dramatic increase and raises possible public health concerns. The increase in non-LSD hallucinogen use occurred while LSD use remained stable at around 4% in 2018 and 2021,” said study co-author Megan Patrick, research professor in the Survey Research Center at U-M’s Institute for Social Research and co-principal investigator of the Monitoring the Future study.

The results, published in the journal Addiction, come from the Monitoring the Future study, conducted by a team of professors at the U-M Institute for Social Research and funded by the National Institute on Drug Abuse, which is part of the National Institutes of Health. In the Monitoring the Future panel study, annual samples of 12th grade students are followed longitudinally into adulthood. The study focuses on substance use and health.

The researchers examined the use of these hallucinogens by sex and found that the use of non-LSD hallucinogens was greater for males. They also found that white young adults used such hallucinogens at a higher rate than Black young adults. Use of non-LSD hallucinogens was also greater for those whose parents had a college education, a proxy for socioeconomic status.

While Monitoring the Future does not identify whether young adults were using these drugs recreationally or because they believed their use to be of therapeutic benefit, previous research has shown that nonmedical hallucinogen use is associated with risks of substance use disorders, injury including self-harm and anxiety, according to the study.

“The use of psychedelic and hallucinogenic drugs for a range of therapeutic uses is increasing, given accumulating yet still preliminary data from randomized trials on clinical effectiveness,” said Katherine Keyes, professor of epidemiology at Columbia Mailman School and lead author of the study. “With increased visibility for medical and therapeutic use, however, potentially comes diversion and unregulated product availability, as well as a lack of understanding among the public of potential risks.”

The survey did not query whether young adults used non-LSD hallucinogen for a therapeutic or medical reason.

“However, approved therapeutic use of psychedelics under a trained health professional’s care remains uncommon in the U.S., thus the trends we observe here are undoubtedly in nonmedical and nontherapeutic use,” Keyes said.

In each survey across young adulthood, from ages 19 to 30, the participants were asked: “How often in the past 12 months have you used LSD?” They were also asked if they had used hallucinogens other than LSD such as mescaline, peyote, “shrooms” or psilocybin, or PCP. Responses ranged from none to 40 times or more. Of the non-LSD drugs listed, “shrooms”/psilocybin had the highest prevalence.

“The use of hallucinogens other than LSD, such as psilocybin in so-called ‘shrooms,’ has increased among young adults in the U.S. This is a rising concern for young adult health,” Patrick said. “We will continue to track these trends to see if the increases continue. We need additional research, including about the motives for hallucinogen use and how young adults are using these substances, in order to be able to mitigate the associated negative consequences.”

The research was supported by the National Institute on Drug Abuse of the National Institutes of Health under award numbers R01DA016575 and R01DA001411.