Roland Griffiths, PhD, is a professor in the departments of Psychiatry and Neurosciences at the Johns Hopkins School of Medicine whose research has focused on the behavioral and subjective effects of mood-altering drugs. His research has been largely supported by grants from the National Institutes of Health, and he is author of over 370 scientific publications. He has conducted extensive research with sedative-hypnotics, caffeine, and novel mood-altering drugs. In 1999, he initiated a research program investigating the effects of the classic psychedelic psilocybin that includes studies 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, treatment of cigarette smoking cessation, and treatment of major depression. Planned future studies include assessing psilocybin effects in early Alzheimer’s disease and a study of psilocybin treatment of anorexia. Brain imaging studies (fMRI and PET) are providing insight into the underlying neural effects that account for unique features of psychedelic experiences. The Hopkins laboratory has also conducted a series of internet survey studies characterizing unusual psychedelic experiences including mystical-type, challenging, and near-death-like experiences.