Denver Health’s Rocky Mountain Poison & Drug Safety (RMPDS) released on Mar. 12 new peer-reviewed research that measures the effect of psychedelic policy reform on psilocybin use in the United States.
The study, published in the Journal of the American Medical Association, is significant because it provides evidence-based insights into how decriminalization policies have influenced the use of psilocybin, also known as magic mushrooms. As more states consider changes to psychedelic laws, understanding these impacts is important for policymakers and public health officials.
Researchers at RMPDS used national survey data and advanced statistical methods to compare actual outcomes in Colorado and Oregon with hypothetical scenarios where decriminalization did not occur but other factors remained constant. This approach allowed them to isolate the independent effect of policy change from broader cultural or media influences. “This study answers the question policymakers actually face: How many additional people used a substance because the law changed?” said Joshua Black, PhD, MS, Senior Statistical Scientist at RMPDS. “Answering that question requires causal inference methodology, not just trend reporting.”
The findings show that in Oregon, decriminalization was linked to a 2.1-percentage-point increase in annual psilocybin use—an estimated 70,000 to 90,000 additional people each year. In Colorado, there was a 1.8-percentage-point increase, representing about 85,000 to 110,000 more users annually; however, this result was not statistically significant due to a shorter observation period after policy change. The study also found that much of the increased use in Oregon occurred outside regulated clinical settings.
By accounting for demographic and socioeconomic factors and controlling for national trends, RMPDS researchers say their work marks an advancement in evaluating drug policy effects across different substances. The results suggest that as states consider decriminalization or regulated access models for psychedelics, they must balance potential therapeutic benefits with public health risks such as impaired cognition or cardiac issues outside clinical environments.
“These findings underscore a critical reality for policymakers and public health leaders,” said Kate Reynolds, MPH, Director of Research at RMPDS. “As psychedelic policies evolve, the greatest public health impacts are likely happening outside regulated systems. RMPDS is uniquely positioned to help governments understand and anticipate those impacts with independent, data-driven evidence.”
