The efficacy, safety and tolerability of the FAAH Inhibitor PF-0447845 in reducing cannabis use will be studied in a 4-site randomized, double-blind, placebo-controlled, parallel-group, outpatient clinical trial comparing PF-04457845 (4mg) and placebo in DSM-5 CUD individuals. Participants will be randomized in a 1:1 ratio to either PF-04457845 or placebo using random block sizes of 2 and 4, stratified by site and degree of cannabis use. Participants will receive motivational interviewing for 2 weeks before being randomized to receive study medication to make a quit attempt within the first week of treatment. Participants will receive active or placebo PF-04457845 for 8 weeks during which time they will be evaluated weekly in face to face visits. In addition, daily assessment of adherence to study medication and cannabinoid use will be conducted daily by cellphone. Measures of cannabinoid exposure (self-reported and urine toxicology), and problems related to the use of cannabis, will be assessed.
