Adding voucher-based incentives to coping skills and motivational enhancement improves outcomes during treatment for marijuana dependence

Sixty individuals seeking outpatient treatment for marijuana dependence were randomly assigned to 1 of 3 treatments: motivational enhancement (M), M plus behavioral coping skills therapy (MBT), or MBT plus voucher-based incentives (MBTV). In the voucher-based incentive program, participants earned vouchers exchangeable for retail items contingent on them submitting cannabinoid-negative urine specimens. MBTV engendered significantly greater durations of documented marijuana abstinence during treatment compared with MBT and M, and a greater percentage of participants in the MBTV group compared with the MBT or M groups were abstinent at the end of treatment. No significant differences in marijuana abstinence were observed between the MBT and M groups. The positive effects of the voucher program in this study support the utility of incentive-based interventions for the treatment of substance dependence disorders including marijuana dependence.