Hallucinogen use in the United States, 2021–2023: Diverging trends and subgroup patterns

Background: While interest in the therapeutic and recreational use of hallucinogens has increased, national surveillance often reports use in aggregate, potentially masking shifting trends among pharmacologically distinct substances. This study assessed trends in specific hallucinogens from 2021 to 2023 and identified correlates of use, with particular attention to subgroup patterns in populations commonly prioritized for prevention and access-focused interventions. Methods: Using nationally representative NSDUH data (2021-2023; ages ≥12), we estimated annual past-year prevalence of LSD, PCP, ecstasy (MDMA), ketamine, Salvia divinorum, and tryptamines (including DMT). We fit survey-weighted logistic regression models with year (continuous) to assess trends and pooled multivariable models to examine demographic correlates. Results: Although overall past-year hallucinogen use was stable (2.83 % [95 % CI: 2.52-3.14] in 2021; 2.82 % [2.52-3.12] in 2023), substance-specific trends diverged. LSD declined (aOR per year=0.83, 95 % CI: 0.75-0.93), from 0.88 % (0.72-1.04) in 2021-0.58 % (0.47-0.68) in 2023. Ketamine increased (aOR=1.11, 95 % CI: 1.02-1.21), from 1.61 % (1.42-1.80) to 1.91 % (1.67-2.16). Ecstasy/MDMA and tryptamines were stable, and PCP and Salvia remained rare. Use concentrated among young adults and males; adjusted models indicated higher odds among uninsured respondents and those below the federal poverty level. Conclusions: Despite stable overall hallucinogen prevalence, significant increases were observed for ketamine alongside declines for LSD, suggesting a shifting landscape of hallucinogen use. Substance-specific monitoring may better inform screening, prevention, and harm-reduction efforts than aggregate hallucinogen indicators, especially as ketamine's medical availability expands and disparities in access to mental health treatment persist.