Motivational enhancement treatment in outpatient addiction centers: A multisite randomized trial.

Background/objectives: Motivational Enhancement Treatment in Spanish (METS) is a brief intervention aimed at resolving patient ambivalence towards behavior change that has demonstrated efficacy in substance use disorder treatment to reduce use and increase treatment engagement in different populations. In order to have evidence for its implementation in Mexico, a multi-site, randomized, two-arm, controlled clinical trial was conducted at three outpatient addiction treatment centers in the country to compare the effect of METS with Counseling as Usual (CAU).

Method: One hundred and twenty patients were randomized to receive three sessions of METS ( = 54) or CAU ( = 66) during the first four weeks of treatment and were assessed during the following 12 weeks. Primary outcome measures were self-reported days of substance use and of treatment services utilization, which were tested using Generalized Estimating Equations.

Results: Results associated both conditions with significant changes in substance use over, whereas there were no differences between conditions in substance use or in service utilization.

Conclusions: Findings do not support the hypothesis that METS is more effective than CAU, but suggest that brief interventions at treatment initiation may improve patient outcomes.