Reinforcing Abstinence and Treatment Participation among Offenders in a Drug Diversion Program: Are Vouchers Effective?

This study assessed a 26-week voucher-based intervention to reinforce abstinence and participation in treatment-related activities among substance-abusing offenders court referred to outpatient treatment under drug diversion legislation (California's Substance Abuse and Crime Prevention Act). Standard treatment consisted of criminal justice supervision and an evidence-based model for treating stimulant abuse. Participants were randomly assigned to four groups, standard treatment (ST) only, ST plus vouchers for testing negative, ST plus vouchers for performing treatment plan activities, and ST plus vouchers for testing negative and/or performing treatment plan activities. Results indicate that voucher-based reinforcement of negative urines and of treatment plan tasks (using a flat reinforcement schedule) showed no statistically significant effects on measures of retention or drug use relative to the standard treatment protocol. It is likely that criminal justice contingencies had a stronger impact on participants' treatment retention and drug use than the relatively low-value vouchers awarded as part of the treatment protocol.