A systematic review of reinforcement-based interventions for substance use: Efficacy, mechanisms of action, and moderators of treatment effects.

BACKGROUND

Brief reinforcement-based psychosocial interventions such as behavioral activation (BA) and behavioral economics (BE) address imbalances in the reinforcement system that are strongly implicated in substance use. The present study reviewed a growing body of intervention studies that tested the efficacy of BA or BE in addressing substance use outcomes. The study also reviewed a smaller body of evidence exploring mechanisms of action and moderators of treatment efficacy for substance use outcomes.

METHOD

A comprehensive literature search of four databases was conducted to identify studies that tested either BA or BE interventions targeting outcomes and/or mechanisms of action specific to substance use. The search yielded 12 studies that met these criteria. Ten studies reported main outcomes of BA/BE interventions targeting substance use outcomes (N = 7 BA; N = 3 BE). Two additional studies addressed mechanisms of change by conducting secondary analyses of data from one of the other ten studies. Eight of the twelve studies tested mechanisms of change and/or moderators related to substance use.

RESULTS

Among all ten outcome studies, 100% provided evidence suggesting efficacy of BA/BE in targeting substance use and/or use-related problems. In 90% (9/10) of studies, the BA/BE intervention condition evidenced significantly higher abstinence rates compared to controls and/or significant decreases in substance use from baseline. Most studies that assessed substance use-related problems (83%; 5/6) reported significant decreases in use-related problems. The majority of studies (80%; 8/10) reported medium to large effect sizes. The pattern of findings was similar for BA and BE interventions. Eight studies assessed change in mechanism of action and 38% (3/8) identified mechanisms of action, however, only two conducted a formal test of whether this variable mediated the relationship between condition and outcome. Two studies tested and identified significant moderators of treatment efficacy.

CONCLUSIONS

Preliminary evidence supports the efficacy of reinforcement-based interventions in targeting substance use outcomes. The mechanisms driving BA/BE efficacy and factors that may moderate treatment effects are not sufficiently clear from the studies available and require further examination, although existing data does suggest promise and provides clues for next steps.