Recorded June 22, 2023 at the Psychedelic Science Conference in Denver, Colorado. Roland Griffiths, Ph.D., is Professor in the Departments of Psychiatry and Neurosciences and Founding Director of the Center for Psychedelic and Consciousness Research at the Johns Hopkins University School of Medicine. His principal research focus in both clinical and preclinical laboratories has been on the behavioral and subjective effects of mood-altering drugs and he is author of over 400 scientific publications and has trained more than 50 postdoctoral research fellows. About 20 years ago, he initiated a research program investigating effects of the classic psychedelic substance psilocybin. Completed and ongoing studies include those in healthy volunteers, in beginning and long-term meditators, and in religious leaders. Therapeutic studies with psilocybin include treatment of psychological distress in cancer patients, major depressive disorder, nicotine addiction, anorexia nervosa, and several other psychiatric disorders. Related studies of brain imaging and drug interactions are examining pharmacological and neural mechanisms of action. His research group has also conducted a series of survey studies characterizing and comparing various naturally-occurring and psychedelic experiences resulting in enduring changes in beliefs, attitudes, moods, and behavior.