Psilocybin, peyote, mescaline, and lysergic acid diethylamide (LSD) use in a nationally representative population by cancer history.

e22518 Background: Classic psychedelics (Peyote, Psilocybin, Mescaline, and LSD) are re-emerging in the oncology toolbox. Peyote is the oldest known psychedelic, yet underexplored in clinical research. Preclinical studies suggest its extract stimulates lymphocyte proliferation, kills tumor cells, and may regulate sleep. This study aims to estimate the prevalence of classic psychedelic use among a US-representative sample of adults with and without a history of cancer. Methods: Data ( N= 208,220, weighted N: 239,589,661) from adults >18y in the 2015 - 2019 National Surveys on Drug Use and Health (52.8% female, 68.4% non-Hispanic White, 45.6% aged ≥50y) were analyzed to estimate lifetime classic psychedelic use among those with no cancer history, past history (diagnosed > 1y ago), or recently (≤1y ago) diagnosed. Weighted prevalence of psychedelic use, 95% confidence intervals, and adjusted (sex, race, income, education) odds ratio were calculated using logistic regression analysis in SAS. Results: Overall, 6.2% had a cancer history and 14.0% reported lifetime classic psychedelics use. LSD was the most prevalent in the sample (10.6%, 95% CI:10.4-10.8) compared to Psilocybin (9.6%, 95% CI: 9.4-9.9), Mescaline (3.1%, 95% CI:3.0-3.2), and Peyote (2.3%, 95% CI:2.2-2.4). Psychedelic use was lowest in adults with past cancer diagnosis (12.3%, 95% CI:11.4-13.1) vs recently diagnosed [14.0% (95% CI:12.0-16.0] and cancer naive (14.1%, 95% CI:13.8-14.4). Each classic psychedelic was used more often among recent cancer diagnosed adults than past diagnosed (p < 0.05). Specifically, LSD (11.1%, 95% CI:9.3-12.9 vs 9.3%, 95% CI:8.5-10.0), Psilocybin (8.3%, 95% CI:6.6-10.0 vs 7.3%, 95% CI: 6.7-8.0), Mescaline (5.4%, 95% CI:4.0-6.8 vs 4.6%, 95% CI: 3.9-5.2), and Peyote (3.7%, 95% CI: 2.5-5.0 vs 2.9%, 95% CI: 2.5-3.4) use was higher in recently diagnosed cancer patients than past diagnosed. There were no significant differences in age, except among Peyote. Among 18-to-34-year-olds, recent cancer patients had 3-fold greater odds (aOR:3.55, 95%CI: 1.11-11.31) of using peyote vs cancer naïve. In ≥50-year-olds, those with past cancer diagnosis had 21% lower odds (aOR:0.79, 95% CI:0.63-0.97) of using peyote vs cancer naïve. Conclusions: Results suggest differential psychedelic use by cancer history and age. These findings, while limited by temporality of diagnosis and initiation of psychedelic use, underscore the need to investigate reasons and long-term impact of specific psychedelic use with more rigor among adults with a cancer history.