Randomized clinical trial examining duration of voucher-based reinforcement therapy for cocaine abstinence.

Background: This is the first study to systematically manipulate duration of voucher-based reinforcement therapy (VBRT) to see if extending the duration increases abstinence during and following VBRT.

Methods: We randomized cocaine-dependent methadone-maintained adults to Standard (12 weeks; n=62) or Extended (36 weeks; n=68) VBRT and provided escalating voucher amounts contingent upon urinalysis verification of cocaine abstinence. Urinalysis was scheduled at least every 2 weeks during the 48-week study and more frequently during VBRT (3/week) and 12 weeks of Aftercare (2/week).

Extended voucher-based reinforcement therapy for long-term drug abstinence.

Objective: To determine whether longer durations of voucher-based reinforcement therapy (VBRT) increase long-term abstinence compared to standard durations.

Methods: Cocaine-abusing or dependent methadone-maintenance patients (N = 130) were randomized to receive either Standard (12-week; n = 62) or Extended (36-week; n = 68) VBRT. Participants provided 3 urine samples weekly during VBRT, and each cocaine-negative sample produced a voucher exchangeable for goods and services.

Resets do not appear to increase the rate of adverse events or prolong relapse in voucher-based reinforcement therapy.

Voucher-based reinforcement therapy (VBRT) is an efficacious contingency management intervention for substance use disorders that provides escalating voucher values to reinforce continuous abstinence and typically resets escalated values to the initial low level upon detection of drug use. The objective of this study involving 130 methadone-maintained outpatients receiving VBRT was to investigate whether resets (a) increase risk for adverse events (AEs) and (b) delay return to abstinence in relation to magnitude of voucher reset. Weeks following resets were examined for increased likelihood of AEs using a Poisson regression.

Interdependent group contingency management for cocaine-dependent methadone maintenance patients.

Contingency management (CM) for drug abstinence has been applied to individuals independently even when delivered in groups. We developed a group CM intervention in which the behavior of a single, randomly selected, anonymous individual determined reinforcement delivery for the entire group. We also compared contingencies placed only on cocaine abstinence (CA) versus one of four behaviors (CA, treatment attendance, group CM attendance, and methadone compliance) selected randomly at each drawing.