The Rise of Psilocybin Use in the United States: A Multisource Observational Study

Background

Psilocybin is being studied as a potential treatment of mental health and substance use disorders. As the first hallucinogenic substance decriminalized in some states within the United States, patterns of psilocybin use have likely changed.

Objective

To quantify change in prevalence and health care utilization of psilocybin users between 2014 and 2023.

Methods

We included 5 nationally representative data sets: the National Survey on Drug Use and Health (NSDUH), the Survey of Non-Medical Use of Prescription Drugs (NMURx), Monitoring the Future (MTF), the National Poison Data System (NPDS), and the National Hospital Ambulatory Medical Care Survey (NHAMCS) (Table) (1-5). Psilocybin use prevalence estimates were calculated annually and plotted using the appropriate design-based adjustments. The relative change and 95% CI in estimates between 2019 and 2023 were calculated; 2019 was selected as the reference for change over time because this was the first year that psilocybin legalization policy changed anywhere within the United States.

Findings

Psilocybin use across data sets was relatively stable before 2019. Lifetime use among adults (aged ≥18 years) increased from 10.0% (95% CI, 9.7% to 10.3%) in 2019 to 12.1% (CI, 11.6% to 12.6%) in 2023, from 25 to 31.3 million (NSDUH). Lifetime use among adolescents (aged 12 to 17 years) increased from 1.1% (CI, 0.9% to 1.3%) in 2019 to 1.3% (CI, 1.0% to 1.6%) in 2023, from 285 000 to 344 000 (NSDUH).