Measurement of substance-free reinforcement in addiction: A systematic review

A robust body of theoretical and experimental work highlights the influence of alternative, substance-free rewards on decisions to use alcohol and other drugs. However, translational applications have been limited in part by the lack of consensus on how to measure substance-free reinforcement in applied and clinical settings. The current study summarizes extant research utilizing self-report reinforcement or reward methodologies, and critically reviews the psychometric properties of the available measures. These studies (N = 50) fell into three categories: measures of recent substance-related and substance-free activity participation and enjoyment (n = 32), measures of time or monetary resource allocation (n = 15), and rating scale measures of reward availability and experience (n = 8). The available research suggests that, consistent with experimental laboratory research and with behavioral economic predictions, there is an inverse relation between substance-free reinforcement and substance use. These studies also support the clinical utility of these measures in predicting substance use severity and course. Reinforcement measures could be improved by enhancing content validity, multimethod convergent validity, and generalizability.