Effectiveness of Motivational Interviewing and Motivational Enhancement Therapy in the Treatment of Stimulant Use Disorders

Background and Purpose: Stimulant use disorder is becoming increasingly pervasive, both in the United States as well as around the world. The reported number of overdose deaths from stimulants increased sixfold between January 2015 and March 2023. There are multiple interventions and treatment methodologies applied to individuals with stimulant use disorder, including motivational approaches. Motivational Interviewing (MI) and Motivational Enhancement Therapy (MET) have been utilized as treatment approaches with this challenging population, both independently as well as augmented with other treatment modalities. To understand and examine the effectiveness of MI and MET when applied to individuals with stimulant use disorder, a scoping literature review was completed. The results from this review provide valuable insight around whether MI and MET are effective with stimulant use disorder, and which augmentations or implementations work, offering practical implications for social work practice.

Methods: Research databases PsycINFO, MEDLINE, SocINDEX, and Psychology and Behavioral Sciences Collection were searched using the following terms: “Motivation* Interview* OR MI OR Motivational* Enhancement Therapy AND cocaine OR methamphetamine OR amphetamine OR stimulant*.” In addition, the Cochrane Library database of clinical trials, systematic reviews, and meta-analyses was searched, as well as the Motivational Interviewing Network of Trainers (MINT) database of MI-focused controlled trials. Two reviewers participated in the screening process and discrepancies around inclusion/exclusion were discussed and resolved.

Results: In total, 22 articles were included in the review. Sixteen were experimental designs, four were quasi-experimental including a control or comparison group without randomization, and two were non-experimental and contained only a single group. The outcomes examined included drug use, addiction severity, change readiness, treatment attendance/adherence, treatment experience, cognitive skills and decision-making, high-risk behaviors, self-efficacy, and others. Most of the studies were conducted in the United States, while some were completed in the United Kingdom, South Africa, Asia, and South America. Of the 17 studies examining drug use and addiction severity outcomes, the literature shows no conclusive evidence about the efficacy of MI or MET with stimulant use disorders. There are significant differences in the dosage and type of implementation of motivational interventions in the literature that make it challenging to compare them with each other.

Conclusions and Implications: Motivational Interviewing was designed to be an approach rather than an intervention. It is a way of talking with people about change and growth to strengthen their motivation and commitment. Measuring MI as a standalone treatment methodology is a challenge. It was intended to be utilized as a bridge to help individuals become willing to participate in treatment. The studies that examined motivational approaches in conjunction with other established SUD evidence-based interventions, as intended by the developers, yielded outcomes that are much more promising. Stimulant use disorder, especially methamphetamine use disorder, presents differently than previously studied addictions. Additional research is needed to determine how to effectively address this persistent and escalating issue. Further research is necessary on the dosing and sequencing of MI and MET sessions with augmented treatment regimens along with fidelity assessment for the motivational component.