Contingent reinforcement sustains post-detoxification abstinence from multiple drugs: a preliminary study with methadone patients.

This study examined the efficacy of a urinalysis-based contingency management program for preventing relapse to abused drugs following a brief residential detoxification. Fourteen methadone maintenance patients who were chronic benzodiazepine users were enrolled in a 7-day inpatient benzodiazepine detoxification and randomly assigned to receive Contingency Management (N = 7) or Standard Care (N = 7) therapy upon return to outpatient methadone treatment. In the Contingency Management condition, a methadone take-home dose or a US $25 voucher (patient's choice) could be earned for each urine sample submitted on a Monday, Wednesday or Friday that was free of opiates, cocaine and benzodiazepines. Data analysis and interpretation focused on within-group post-hoc differences due to group differences on employment and legal status, potentially confounding baseline variables. Repeated measures analysis of variance showed that Contingency Management patients submitted significantly more drug-free urine samples during the intervention compared to pre-detoxification (p < 0.01), whereas no significance changes were observed from pre- to post-detoxification in the Standard Care patients. Employment and legal status of patients may have facilitated response to contingency management procedures, but did not prevent relapse when contingency management procedures were withdrawn. Overall, these preliminary results suggest that abstinence-based contingency management is a promising strategy for preventing relapse to multiple drugs of abuse in a subset of methadone maintenance patients when abstinence has been initiated through brief inpatient treatment.