Objective: Contingency management (CM) is efficacious in reducing drug use. Typically, reinforcers are provided on an individual basis to patients for submitting drug-negative samples. However, most treatment is provided in a group context, and poor attendance is a substantial concern. This study evaluated whether adding CM to group-based…

To examine the effect of reinforcer density in prize-based abstinence reinforcement, heroin/cocaine users (N = 116) in methadone maintenance (100 mg/day) were randomly assigned to a noncontingent control group (NonC) or to 1 of 3 groups that earned prize draws for abstinence: manual drawing with standard prize density (MS) or computerized drawing…