All participants gave their written, informed consent before participating in this study. Participants were students at the University of Colorado, Boulder between the ages of 18 and 25 years. Individuals were excluded from the study if they were taking any psychotropic medications, currently using any recreational drugs other than marijuana or attempting to quit smoking marijuana. In addition, participants had to be daily marijuana smokers during the past year (smoke marijuana at least once a day, 5–7 days per week). Participants received $50 for participating in this study. The University of Colorado Human Research Committee approved all procedures.
