Many individuals intending to start extended-release naltrexone (XR-NTX) do not and most who do start XR-NTX discontinue treatment prematurely, two factors that limit its clinical utility significantly. XR-NTX appears to decrease opioid use but there are few experimental demonstrations of this effect.

On multiple fixed-ratio schedules, pausing is extended at the start of a component ending in a small reinforcer (a lean component) but only when this component follows a component ending in a large reinforcer (a rich component). In two experiments, we assessed whether a stimulus correlated with a lean component is aversive and how its function is affected by the preceding component. In Experiment 1, pigeons responded on mixed fixed-ratio schedules ending in large or small reinforcers. Observing responses converted the mixed schedule to a multiple one by producing a stimulus correlated with the current component. Overall, the lean stimulus did not suppress observing, suggesting that it was not sufficiently aversive. In Experiment 2, an escape procedure was used, and pigeons could convert a multiple schedule to a mixed one by pecking a key to remove the discriminative stimuli. Pigeons escaped from the lean-schedule stimulus more than they did from the rich one. For two pigeons, this effect was enhanced when a rich component preceded the lean stimulus. The results indicate that a stimulus correlated with the leaner of two reinforcement schedules can acquire aversive functions, but observing and escape procedures may differ in their abilities to detect this effect.

Research on a model Therapeutic Workplace has allowed for evaluation of the use of employment in the treatment of drug addiction. Under the Therapeutic Workplace intervention, adults with histories of drug addiction are hired and paid to work. To promote drug abstinence or adherence to addiction medications, participants are required to provide drug-free urine samples or take prescribed addiction medications, respectively, to gain access to the workplace and/or to maintain their maximum rate of pay. Research has shown that the Therapeutic Workplace intervention is effective in promoting and maintaining abstinence from heroin, cocaine and alcohol and in promoting adherence to naltrexone. Three models could be used to implement and maintain employment-based reinforcement in the treatment of drug addiction: A Social Business model, a Cooperative Employer model, and a Wage Supplement model. Under all models, participants initiate abstinence in a training and abstinence initiation phase (Phase 1). Under the Social Business model, Phase 1 graduates are hired as employees in a social business and required to maintain abstinence to maintain employment and/or maximum pay. Under the Cooperative Employer model, cooperating community employers hire graduates of Phase 1 and require them to maintain abstinence to maintain employment and/or maximum pay. Under the Wage Supplement Model, graduates of Phase 1 are offered abstinence-contingent wage supplements if they maintain competitive employment in a community job. Given the severity and persistence of the problem of drug addiction and the lack of treatments that can produce lasting effects, continued development of the Therapeutic Workplace is warranted.