Abstract
INTRODUCTION: This paper aimed to determine the prevalence, demographic correlates and co-occurring substance use patterns of hallucinogen microdosing among young adults in the United States. METHODS: Design: Cross-sectional analysis of data from a nationally-representative cohort study collected in 2022-2023. SETTING: United States. PARTICIPANTS: Sample of 3094 young adults aged 19-30 years in the Monitoring the Future panel study. MEASUREMENTS: Self-reported past-year hallucinogen use and at least one past-year incident of microdosing, demographic characteristics (age, sex, race/ethnicity, college attendance, parental education) and other substance use (alcohol, cannabis, nicotine, other drugs). RESULTS: Past-year hallucinogen use was reported by 9.5% (SE = 0.68) of young adults, with microdosing reported by 6.8% (SE = 0.61). Among those who used hallucinogens, 73.1% (SE = 3.6) engaged in microdosing. Individuals who reported microdosing demonstrated substantially higher rates of other substance use, with odds ratios ranging from 2.53 (95% CI 1.43-4.47) for past-month cigarette use to 37.73 (95% CI 19.72-72.21) for 3+ occasions of past-year cannabis use. Among those who microdosed, 72.4% reported 10+ occasions of past-year alcohol use and 85.8% reported 3+ occasions of past-year cannabis use. There were few significant demographic differences in microdosing, though Black respondents were less likely (OR = 0.43, 95% CI 0.21-0.90) to microdose compared with White respondents. DISCUSSION AND CONCLUSIONS: Approximately 1 in 15 US young adults reported microdosing hallucinogens, with strong associations between microdosing and other substance use. Despite growing interest in potential therapeutic applications of microdosing, the context in which microdosing typically occurs, including patterns of other drug and alcohol use, raises concerns and warrants focused prevention efforts.