Hi! Researchers at The Johns Hopkins University School of Medicine are seeking individuals with some experience using psychedelic drugs (e.g., LSD, mescaline, psilocybin, ayahuasca, salvinorin A) to participate in a research study looking at the effects of salvinorin A on brain activity. Volunteers must be 21 to 50 years old, have no personal or familial history of severe psychiatric illness. Participation involves approximately one screening session (about 5 hours), a 2-hour preparation meeting, and two study sessions (about 2 hours each) involving inhalation of a moderately strong dose of salvinorin A at the Johns Hopkins Bayview Medical Center. One of these sessions includes brain imaging in a MRI scanner. Possible compensation up to $225 for participating. Confidentiality will be maintained for all applicants and participants. To discuss the possibility of volunteering or to learn more about the study: Phone: 410-550-3074 or 410-550-2253 Email: HopkinsPsychedelicStudy@jhmi.edu Principal Investigator: Frederick S. Barrett, Ph.D., Protocol: IRB00131537