Roland Griffiths, Ph.D., is Professor in the Departments of Psychiatry and Neurosciences 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. His research has been largely supported by grants from the National Institute on Health and he is author of over 360 journal articles and book chapters. He has been a consultant to the National Institutes of Health, and to numerous pharmaceutical companies in the development of new psychotropic drugs. He is also currently a member of the Expert Advisory Panel on Drug Dependence for the World Health Organization. He has conducted extensive research with sedative-hypnotics, caffeine, and novel mood-altering drugs. In 1999 he initiated a research program at Johns Hopkins investigating the effects of the classic hallucinogen psilocybin that includes studies of psilocybin-occasioned mystical-type experiences in healthy volunteers, psilocybin-facilitated treatment of psychological distress in cancer patients, psilocybin-facilitated treatment of cigarette smoking cessation, psilocybin effects in beginning and long-term meditators, and psilocybin effects in religious leaders. Drug interaction studies and brain imaging studies (fMRI and PET) are examining pharmacological and neural mechanisms of action. The Hopkins laboratory has also conducted a recent series of internet survey studies characterizing the effects hallucinogen-occasioned mystical experiences, challenging experiences, and effects on substance abuse.