Breaking psychedelic boundaries in public health: emerging ideas with ancient roots.

The modern United States faces significant public health challenges, including a mental health crisis and healthcare systems with numerous shortcomings. At the same time, emerging research on psychedelic substances demonstrates their robust applications for health and well-being, as well as their nuanced risks. While regulators explore how psychedelics can be incorporated into existing healthcare models, patterns of psychedelic use extend beyond clinical settings. These naturalistic or non-clinical applications-for spiritual growth, social bonding, ecological connection, and overall health-have occurred for thousands of years in various cultural contexts. In this critical analysis, we examine historical evidence depicting how psychedelics were utilized in the Americas, before and after European colonization. We highlight the racialized and religious origins of prohibitionist drug policy, as well as U.S. healthcare norms that constrain avenues for mental health, personal choice, and general flourishing. By drawing on interdisciplinary research in clinical mental health, history, anthropology, and medical sociology, we argue for (A.) holistic improvements to narrow mental healthcare models and (B.) an expanded-access posture towards psychedelics that includes non-clinical use scenarios. Our review of existing evidence supports these approaches for improving public mental health.