Pilot Study: Effects of Psilocybin on Behavior, Psychology and Brain Function in Long-term Meditators

This is a pilot study to finalize methods for a larger study being planned for the future. This research is being done to characterize performance of tasks, brain functioning, and the effects of psilocybin in individuals with a long-term meditation practice. There are three different parts of the pilot study: 1. Effects of psilocybin on psychological function: This version of the pilot study will involve 1 or 2 day-long psilocybin sessions, and several meetings and data assessment visits. You will make a total of about 5 to 10 visits to our research unit (the BPRU on the Johns Hopkins Bayview Campus). 2. Performance on behavioral and cognitive tasks: This version of the pilot study will involve completing various behavioral and cognitive tasks at our research unit. You will make a total of about 1-10 visits to our research unit (the BPRU on the Johns Hopkins Bayview Campus). 3. Brain functioning: This version of the study will involve 1 to 3 brain imaging (MRI) measurements. You will make a total of about 2 to 5 visits to our research unit (the BPRU on the Johns Hopkins Bayview Campus). The MRI measurements will be taken at the F.M. Kirby Research Center at the Kennedy Krieger Institute (across the street from the Johns Hopkins Hospital). People who are between the ages of 25 and 80 years old, who have a current, regular meditation practice, and who meet the medical requirements may join.