Study charts rising rates of U.S. psilocybin use across age groups
Among U.S. adults, self-reports of having ever used psilocybin increased from 10.0% in 2019 to 12.1% in 2023, and there was a 201% increase in the rate of psilocybin exposures reported to poison centers, prompting researchers to call for increased education and surveillance of the substance.
The prevalence of lifetime and past-year use of psilocybin increased among all age groups between 2019 and 2023, following decriminalization of the hallucinogenic in some states, research shows.
To quantify the change in prevalence and health care utilization of psilocybin users between 2014 and 2023, researchers assessed five 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, the National Poison Data System, and the National Hospital Ambulatory Medical Care Survey (NHAMCS). The year 2019 was chosen as the reference for change over time as this was the first year that the policy for legalization of psilocybin changed anywhere within the U.S. Findings were published by Annals of Internal Medicine on April 22.
Prior to 2019, psilocybin use across data sets was relatively stable. However, lifetime use among adults ages 18 years or older increased from 10.0% (95% CI, 9.7% to 10.3%) in 2019 to 12.1% (95% CI, 11.6% to 12.6%) in 2023, from 25 to 31.3 million, according to the NSDUH. The data set also showed that lifetime use among adolescents ages 12 to 17 years increased from 1.1% (95% CI, 0.9% to 1.3%) in 2019 to 1.3% (95% CI, 1.0% to 1.6%) in 2023, from 285,000 to 344,000. From 2019, past-year psilocybin use increased 44% among adults ages 18 to 29 years and 188% among adults ages 30 years or older. Prevalence of past-year use among all adults was 2.1% (95% CI, 2.0% to 2.3%) in 2023 but varied by age group (3.5% among young adults and 1.8% among older adults).
An analysis of data from NMURx found that adults who used psilocybin in 2023 were younger (median age, 36.8 vs. 48.2 years) and more likely to be male (52.3% vs. 47.6%) than nonusers. The percentage of psilocybin use was higher in those with mental health or chronic pain comorbidities, including individuals with moderate/severe anxiety symptoms, moderate/severe depression symptoms, and chronic pain. There was a 201% increase in the rate of psilocybin exposures reported to U.S. poison centers among adults, a 317% increase among adolescents, and a 723% increase among children, but just three cases of psilocybin poisoning were recorded by EDs and outpatient facilities between 2015 and 2021, according to NHAMCS data.
The main limitation to the study is that outcomes were self-reported.
While exposures reported to poison centers frequently resulted in interaction with a health care facility (76.7%), “this finding was not reflected in International Classification of Diseases, 10th Revision (ICD-10) codes from NHAMCS,” the authors wrote, suggesting that ICD-10 codes may be an ineffective way to monitor the impact of psilocybin use on health care systems.
Data also showed that the prevalence of past-year adult psilocybin use was higher than estimates for cocaine, LSD (lysergic acid diethylamide), methamphetamine, or illicit opioid use in 2023, the study authors added.
State-level policy changes related to psilocybin may result in people attempting self-treatment with this drug, the authors explained. “Rigorous education and enforcement of dose limits should be considered,” they said. Additional surveillance tools are needed to better characterize psilocybin use, monitor clinical outcomes, and determine impacts on public health, especially in states that have implemented regulated programs, the researchers concluded.