Does contingency management affect motivation to change substance use?

Although substantial evidence favors the efficacy of contingency management (CM) for substance use disorders, few studies have examined the effect of CM on one's motivation to change substance use. One way of conceptualizing motivation to change is by using the stages of change model [Prochaska, J.O., DiClemente, C.C., 1983. Stages and processes of self-change of smoking: toward an integrative model of change. J. Consult. Clin. Psychol. 51, 390–395]. We assessed motivation to change substance use as conceptualized by the stages of change model using the University of Rhode Island Change Assessment (URICA [McConnaughy, E.A., Prochaska, J.O., Velicer, W.F., 1983. Stages of change in psychotherapy: measurement and sample profiles. Psychother. Theor. Res. 20, 368–375]) in 115 patients in community treatment clinics before they were randomized to receive standard treatment or standard treatment plus CM. Motivation was also assessed 3 months later. Patients in both conditions evidenced significant decreases in their motivation scores from pre- to post-treatment. CM neither increased nor decreased motivation relative to the standard treatment condition. Pre-treatment motivation scores were also not related to treatment outcome. Assignment to the CM condition was associated with better treatment outcome as defined by longest duration of abstinence during treatment (LDA). Higher post-treatment motivation was also modestly associated with LDA, but not in all analyses. These findings suggest that CM neither increases nor decreases motivation to change substance use in outpatients receiving treatment at community-based drug-free clinics. Future studies should further examine motivation change in CM treatment using different assessment tools and conceptualizations of motivation, extending these effects to other treatment settings and populations.