From alcohol and other drug treatment mediator to mechanism to implementation: A systematic review and the cases of self-efficacy, social support, and craving

Research designed to establish alcohol and other drug (AOD) mechanisms of behavioral change (MOBC) has centered on what variables mediate the relation between AOD treatment and outcomes. The purpose of this paper was to review this research evidence to identify empirically supported mediators of alcohol and other drug use and related outcomes and then to evaluate their potential as being AOD treatment MOBC. The first phase was a systematic review of reviews (2008–2023) to identify the variables with the strongest empirical support as mediators of AOD treatment effects. Eligible reviews focused on AOD treatment modalities, included empirically tested mediators, and targeted adult samples. The second phase was a systematic review of empirical studies (1990–2023) testing the hypothesis that variables identified in phase one were AOD treatment mediators/mechanisms and then evaluating each eligible stage two study according to the Kazdin and Nock (Journal of Child Psychology and Psychiatry, 44, 1116) criteria. Eligible articles included empirical studies with adult samples attending AOD treatment and empirically tested one of the three treatment mechanisms as a mediator of an AOD-related outcome. Databases were searched in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. This systematic review was not preregistered. The first review of 11 eligible review articles identified self-efficacy, social support, and craving as having the strongest empirical support. The second review captured 48 individual studies. An evaluation of each of these studies by the Kazdin and Nock criteria suggested that they likely are MOBC and therefore are ready for implementation. The implementation of self-efficacy, social support, and craving into clinical practice and training is warranted. Six directions for future research to solidify and generalize empirical support for the case that self-efficacy, social support, and craving are MOBC are presented, as are five implications for clinical practice and training.