MI: Evidence base
Originally developed as a treatment intervention for substance use—evidence base is being developed for other mental health and medical issues.
Since the 1980s the number of research and clinical articles has doubled every three years. In this period there have been more than 1,000 publications and more than 200 randomized clinical trials (Miller & Rollnick, 2009, 2010).
- Two meta-analyses (Lundahl & Burke, 2009; Lundahl et al., 2010) link to support the efficacy of MI in addiction and in other health behaviour change areas (e.g., mental health problems, diabetes, obesity, hypertension, criminal justice, homelessness, HIV/ AIDS).
- In general, treatment trials tend to find that no one intervention is innately superior for all clients under all conditions—this includes MI (Prochaska & Norcross, 2007).
- Research supports the use of MI to enhance treatment engagement and retention, client goal setting and behaviour change, motivation and treatment outcomes (up to three years post-treatment).
- MI has also been researched in a variety of formats, including as a stand-alone treatment intervention (Miller & Rose, 2009); as a brief (i.e., a few minutes) counselling intervention (Herie & Selby, 2007); in combination with other approaches (Miller & Rose, 2009); and in groups (LaBrie et al., 2006).
Challenges in evaluating efficacy
These are not all specific to MI research, but they should be considered in critically assessing the evidence. The following questions raise possible limitations:
- Did the study compare "pure" MI with another intervention? Many practitioners—and research studies—use an eclectic approach, combining MI with other evidence-based interventions, such as cognitive-behavioural therapy or contingency management.
- How was MI fidelity on the part of counsellors ensured? There is evidence that practitioners' self-reports of the interventions they offer may not correspond with what they actually do in a clinical session (Miller et al., 2006).
- What were the studies' inclusion and exclusion criteria? Many research trials exclude the most complex or severely dependent individuals, with positive results that may be statistically, but not clinically, significant (i.e., the results may not reflect the client population seen in real-life practice).
Comparison with other interventions
Keeping these caveats in mind, when MI has been compared with other interventions (treatment as usual), outcomes in the MI condition were found to be effective 75 per cent of the time, with 50 per cent of clients gaining small but meaningful effects, and 25 per cent gaining moderate to strong effects (Lundahl et al., 2010). These results are consistent with research findings for other clinical interventions.
An added benefit of MI over other treatments is that a smaller dose of treatment may be needed; on average, studies have found that MI treatments take an average of 100 fewer minutes, yet produce equal effects (Lundahl et al., 2010).
Herie, M. & Selby, P. (2007, April). Getting beyond "Now is not a good time to stop smoking": Increasing motivation to stop smoking. Smoking Cessation Rounds, 1 (2).
LaBrie, J.W., Lamb, T.F., Pedersen, E.R. & Quinlan, T. (2006). A group motivational interviewing intervention reduces drinking and alcohol-related consequences in adjudicated college students. Journal of College Student Development, 47, 267–280.
Lundahl, B. & Burke, B.L. (2009). The effectiveness and applicability of motivational interviewing: A practice-friendly review of four meta-analyses. Journal of Clinical Psychology, 65, 1232–1245.
Lundahl, B.W., Kunz, C., Brownell, C., Tollefson, D. & Burke, B.L. (2010). A metaanalysis of motivational interviewing: Twenty-five years of empirical studies. Research on Social Work Practice, 20, 137–160.
Miller, W.R. & Rollnick, S. (2009). Ten things that motivational interviewing is not. Behavioural and Cognitive Psychotherapy, 37, 129–140.
Miller, W.R. & Rollnick, S. (2010). What's new since MI-2? Presentation at the International Conference on Motivational Interviewing, Stockholm, Sweden.
Prochaska, J.O. & Norcross, J.C. (2007). Systems of Psychotherapy: A Transtheoretical Analysis (6th ed.). Belmont, CA: Thompson Brooks/Cole.
Miller, W.R. & Rose, G.S. (2009). Toward a theory of motivational interviewing. American Psychologist, 64, 527–537.
Drug and alcohol findings
Drug and Alcohol Findings bridges the divide between UK-relevant research on the effectiveness of responses to drug and alcohol problems and the practitioners who provide those interventions. The project aims to encapsulate the studies' findings, set them in context and explore implications for practice.
MI summaries from Findings
- Motivational interviewing – The Swiss army knife of substance abuse counselling
- Summary of Lundahl B.W, Kunz C., Brownell C. et al. Research on Social Work Practice: 2010, 20(2), p. 137–160.
- Summary of Smedslund G., Berg R.C., Hammerstrøm K.T. et al. Cochrane Database of Systematic Reviews: 2011, 5, Art.No.:CD008063.
- Summary of Jensen C.D., Cushing C.C., Aylward B.S. et al. Journal of Consulting and Clinical Psychology: 2011, 79(4), p. 433–440.
Other summaries of MI research
- What the research says...about motivational interviewing: --summary from MINT
- Efficacy of Motivational Interviewing for Smoking Cessation: A Systematic Review and Meta-Analysis: /
- Foxcroft, DR et al (2014) Motivational interviewing for alcohol misuse in young adults.Cochrane Database of Systematic Reviews. 8, CD007025
- Training professionals in motivational interviewing (evidence scan):
- Mental Elf MI archive: / --summary of research—includes MI with young people