Increasing opiate abstinence through voucher-based reinforcement therapy

Heroin dependence remains a serious and costly public health problem, even in patients receiving methadone maintenance treatment. This study used a within-subject reversal design to assess the effectiveness of voucher-based abstinence reinforcement in reducing opiate use in patients receiving methadone maintenance treatment in an inner-city program. Throughout the study subjects received standard methadone maintenance treatment involving methadone, counseling, and urine monitoring (three times per week). Thirteen patients who continued to use opiates regularly during a 5-week baseline period were exposed to a 12-week program in which they received a voucher for each opiate-free urine sample provided; the vouchers had monetary values that increased as the number of consecutive opiate-free urines increased. Subjects continued receiving standard methadone maintenance for 8 weeks after discontinuation of the voucher program (return-to-baseline). Tukey's posthoc contrasts showed that the percentage of urine specimens that were positive for opiates decreased significantly when the voucher program was instituted (P less than or equal to 0.01) and then increased significantly when the voucher program was discontinued during the return-to-baseline condition (P less than or equal to 0.01). Rates of opiate positive urines in the return-to-baseline condition remained significantly below the rates observed in the initial baseline period (P less than or equal to 0.01). Overall, the study shows that voucher-based reinforcement contingencies can decrease opiate use in heroin dependent patients receiving methadone maintenance treatment.