Matthew W. Johnson, Ph.D. and Mary P. Cosimano, M.S.W. A promising yet inconclusive line of research from the 1950s through 1970s involved hallucinogens in the treatment of addiction. Recent research with non-addicted individuals in our laboratory suggests that psilocybin can occasion mystical-type experiences with enduring personal meaning. Embedding such experiences into addiction treatment may enhance abstinence success. We are conducting a pilot, feasibility study in which psilocybin sessions conducted under highly supportive conditions are combined with cognitive behavioral therapy for tobacco smoking cessation in nicotine-dependent smokers. Measures include biological verification of smoking abstinence and assessments of potential mediating mechanisms of action. Dr. Johnson and Ms. Cosimano have jointly conducted treatment sessions including psilocybin sessions. Dr. Johnson will describe the rationale, methods and preliminary results, and Ms. Cosimano will present in-depth case reports of volunteer psilocybin experiences and smoking cessation efforts. Biographies Matthew W. Johnson, Ph.D. Assistant Professor, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine Dr. Johnson is Assistant Professor of Psychiatry at Johns Hopkins University School of Medicine. He received his Ph.D. in experimental psychology from the University of Vermont, and completed a fellowship in behavioral pharmacology at Johns Hopkins. Dr. Johnson is the principal investigator of an NIH-funded research program to understand the mechanisms of addictive behavior, and is currently investigating the high rates of sexual HIV risk behavior in cocaine dependence. Dr. Johnson also has expertise in investigating the effects of psychoactive drugs in humans, and has conducted human research with psilocybin, Salvia divinorum, dextromethorphan, GHB, cocaine, benzodiazepines, alcohol, nicotine, and caffeine. He has conducted research examining the ability of psilocybin to occasion mystical experience with persisting effects on attitude and behavior. In line with his expertise in both addictions and hallucinogens, he is the principle investigator of an ongoing pilot study examining psilocybin in the treatment of nicotine dependence. Mary P. Cosimano, MSW Graduate Social Worker, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine For 10 years Mary Cosimano has served as a research coordinator and study session guide in the Department of Psychiatry and Behavioral Sciences at the Johns Hopkins University School of Medicine. During that time she has served as a session guide for all five psilocybin studies at Johns Hopkins, and has conducted over 170 sessions. Ms. Cosimano earned her Masters of Social Work from West Virginia University. She worked as a clinician teaching individual and group meditation to breast cancer patients in research at Johns Hopkins, as a behavior modification counselor for weight loss, a school guidance counselor, and has 15 years of experience with direct patient care as a hospice volunteer. Ms. Cosimano has been extensively involved in all five psilocybin studies, as well as Salvia Divinorum and dextromethorphan studies conducted at Johns Hopkins. She will present case descriptions from two volunteers in the psilocybin and smoking cessation pilot study.