Development of a motivational interviewing/acceptance and commitment therapy model for adolescent substance abuse treatment

Christian Thurstone, Madelyne Hull, Julia Timmerman, & Chad Emrick


Current adolescent substance treatment models have important limitations. Motivational interviewing (MI) combined with Acceptance and Commitment Therapy (ACT) may be a promising new approach. The purpose of this study is to develop a manual-standardized MI/ACT intervention for evaluation in future controlled trials.

Participants were 41 adolescents and young adults (ages 12–26 years) consecutively admitted to an urban adolescent substance treatment program and the six therapists who administered the intervention. The intervention was 12 weeks of individual, outpatient, manual-standardized MI and ACT combined with contingency management and psychiatric consultation as needed. The outcome measures were the Outcome Rating Scale (ORS), patient satisfaction questionnaires, proportion of days used non-nicotine substances, qualitative interviews of therapists and the Session Rating Scale (SRS). Wilcoxon signed-rank and paired t-tests were used to determine significant change in pre- and post-intervention measures.

A total of 14 of 23 (61%) youth with pre-intervention ORS scores in the clinical range had end of treatment scores in the non-clinical range and a clinically significant increase of over 5 points. The proportion of youth reaching a week of abstinence was 71% by self-report and 68% by urine drug screen. The proportion of days used at pre-intervention (Mdn = 1.0; IQR 0.4, 1.0) for those with non-zero pre-intervention use (N = 27) was significantly different at post-intervention (Mdn 0.1; IQR 0, 1.0) ( S= 84, p = 0.0014). The average SRS score was 37.9 (SD = 2.2), indicating a high level of satisfaction.

This study demonstrates the initial feasibility of using an MI/ACT model in adolescent substance treatment. A small-scale, randomized controlled trial of MI/ACT is needed to evaluate the feasibility of larger, controlled trials and to determine the sample size that will be needed for an adequately powered study.

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