A Multicenter Phase 1 Safety and Tolerability Trial of Psilocybin in Healthy Older Adults

This study plans to learn more about the safety and tolerability of psychedelic administration (psilocybin) in healthy older adults ages 65-85. The purpose of this study is to learn whether psilocybin, a psychedelic compound, can be given safely to older adults. We want to understand how psilocybin affects the body and mind, including blood pressure, heart rhythm, and mood. We also want to see how the body processes psilocybin (how quickly it is absorbed and cleared) and whether it affects thinking, memory, or wellbeing. * Primary Objective: Evaluate the safety and tolerability of psychedelic administration in two cohorts of healthy older adults. * Cohort 1a Psilocybin Moderate Dose: 2 doses of oral psilocybin (10mg and then 25mg) 30 days apart. * Cohort 1b Psilocybin High Dose: 2 doses of oral psilocybin (15mg and then 30mg) 30 days apart. * Secondary Objectives: Evaluate the pharmacokinetics of Psilocybin for each Cohort of healthy older adults. * Exploratory Objectives: Evaluate patient-reported outcomes related to Psilocybin administration (e.g., psychedelic experience and well-being) in each Cohort. Assess the relationships between the pharmacokinetic profile, safety endpoints, and patient-reported outcomes in each Cohort.