This trial is an open-label pilot study (N = 10) designed to assess the effects of psilocybin in alcohol dependent participants, demonstrate the feasibility of the integrated behavioral/pharmacologic intervention, and provide preliminary outcome and safety data. Participants will receive psilocybin orally in two all-day administration sessions, conducted in a secure outpatient psychiatric setting, in a dose range that has been well-tolerated in recent studies. Psilocybin administration will occur in the context of a behavioral intervention including a total of 12 sessions over 12 weeks, incorporating Motivational Enhancement Therapy (MET (Miller, Zweben et al. 1992; Miller 1995), based on Motivational Interviewing (Miller and Rollnick 2002)) with booster sessions, as well as preparation before and debriefing after the psilocybin administration sessions. The MET will incorporate attention to spirituality as well as drinking behavior as a primary subject of change. Drinking outcomes and changes in several potential mediators of treatment effect, including motivation, self-efficacy, craving, depression, anxiety, and spiritual dimensions of the experience, will be measured during treatment and for 24 weeks after the end of treatment. The investigators hypothesize that drinking will decrease following the psilocybin sessions, and that increases in motivation, self-efficacy, and spirituality (primary contrast 12 weeks vs. baseline) will be observed among study participants.