Psilocybin mushrooms and public health in Brazil: a low-risk adverse event profile calls for evidence-based regulatory discussions

Background: Due to inconsistencies in current drug policies and regulatory frameworks, there is a lack of knowledge regarding the adverse event profile of psilocybin mushrooms in Brazil. Our study investigated whether these fungi have potential for abuse and pose a risk to public health. Methods: We conducted a retrospective cross-sectional study following the STROBE Initiative guidelines, using data from the Sistema de Agravos de Notificacao (SINAN) to obtain a representative sample of adverse events reported between 2007 and 2022. Participants were divided into three groups: drug abuse, psilocybin mushrooms, and unknown mushrooms. The clinical outcomes evaluated were non-hospitalization, hospitalization, and death. To analyze associations between categorical variables, we applied the Chi-square test. Results: During the study period, 112,451 individuals sought medical attention due to adverse events associated with drug abuse. Men (n = 79.514; 70.7%), whites (n = 37.565; 33.4%), and the 26-35 age group (n = 29.163; 25.9%) were the most well-represented (p < 0.001). Alcohol (n = 71.824; 49.2%) (p < 0.001) was the primary toxic agent. Hospitalization and mortality rates in the drug abuse group were 19.5% (n = 21,923) and 1.8% (n = 2035), respectively. Psilocybin mushroom group included 13 adverse events, which represents 0.02% of all hospitalizations (n = 6; 46.2%). Unknown mushroom group accounted for 51 adverse events, comprising 0.04% of hospitalizations (n = 12; 23.5%). There were no fatalities in either the psilocybin or unknown mushroom groups. Most hospitalizations involved alcohol (45.0%) and deaths represented mainly by cocaine (33.3%). Conclusion: While our findings suggest that psilocybin mushrooms present a low-risk profile of adverse events, underreporting is a possibility. Given the increasing public interest in psilocybin mushrooms, this study underscores the importance of evidence-based regulatory discussions to prevent arbitrary arrests and ensure safe access to psilocybin for both clinical and ceremonial purposes.