Real-world use, safety, and mental health efficacy of regulated psilocybin services in Oregon and Colorado

<jats:p>Oregon (OR) and Colorado (CO) were the first states to enact regulations for provision of psilocybin with support of licensed "facilitators." As more states and countries adopt similar policies, informed public policy decisions require that client characteristics and rationale for using psilocybin, psilocybin dosing practices, mental health outcomes, and adverse events are understood. We performed a retrospective observational study of responses for 2363 individuals receiving psilocybin at OR and CO regulated service centers. Clients and facilitators entered data before and after receiving psilocybin, including the Mystical Experience Questionnaire-30 (MEQ-30), Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), and World Health Organization Well-Being Index-5 (WHO-5). Preexisting mental health issues were common (66%) in participants. Psilocybin doses ranged from 1-95 mg, with a mean total of 28∙8 mg. We observed improvements of 49% in PHQ-9 scores, 51% in GAD-7 scores, and 22% in WHO-5 scores at two-weeks after dosing. MEQ-30 scores were dose-dependent. Changes in PHQ-9 and GAD-7 scores were not different for psilocybin doses ≤30 mg and &gt;30 mg, and only weakly correlated with MEQ-30 scores. There were 94 mild adverse events during and after dosing, five more serious events not clearly related to treatment, and evidence of possible risk of increased suicidality. Study limitations include open label administration, self-reporting, loss of participants for follow-up, and a short 2-week post-dosing end-point. We conclude that psilocybin services, delivered within these regulated frameworks, is associated with improvements in mental health in real world populations, however, more robust monitoring is needed to ensure safety.</jats:p>