In 2015 a systematic litterature review on Motivational Interviewing and its effects on health behavior change, was published.
British researchers went through lots of studies on the subject, and evaluated how it fared when it came to people starting to exercise, drink less alcohol, etc.
MI is a way of inducing behavior change, by a specific type of dialogue which has four key parts:
- Expressing empathy towards the persons current situation.
- Developing a discrepancy between the persons current behaviors and the future steps needed to reach important personal goals.
- Avoiding argumentation.
- Involving the person in the problem-solving part.
MI also has a further, more illusive part sometimes referred to as "change talk", where the client by him/herself utters phrases that point to a desirability for change, coming from the clients own realisation of the undesirability of their current state. This is often thought of as the causal pathway to change in MI.
Out of the 33 studies included - that all dealt with behavior change relating to health, researchers found only 50% reported significant positive change after the intervention. Several, actually the majority of studies included, suffered from various methodological problems lending it difficult if not impossible to actually judge if MI or something else was being measured. Oftentimes, MI interventions seemed to involve a host of different methods that actually aren't theoretically described in MI. Furthermore, there was really no study that investigated the causal link between "change talk" and behavior change, even though some measures seemed to indicate that.
In summary, the authors concluded that MI appears to show some evidence of working, but in the future more rigorous studies isolating specific MI-components, need to be done.
Katie Morton, Mark Beauchamp, Anna Prothero, Lauren Joyce, Laura Saunders, Sarah Spencer-Bowdage, Bernadette Dancy & Charles Pedlar(2015)The effectiveness of motivational interviewing for health behaviour change in primary care settings: a systematic review,Health Psychology Review,9:2,205-223,DOI:10.1080/17437199.2014.882006