Motivational interviewing

Miller introduced MI in 1983 while treating problem drinkers, drawing on his observations that therapist empathy and client self-efficacy predicted outcomes better than confrontation.² He later collaborated with Stephen Rollnick, and their 1991 book Motivational Interviewing formalized the approach. The method evolved from a 'style' to a structured clinical method, with the third edition (2013) emphasizing the 'spirit' of partnership, acceptance, compassion, and evocation.³

MI is grounded in four overlapping processes: engaging (building a working alliance), focusing (developing a clear direction), evoking (eliciting the client's own arguments for change), and planning (formulating a concrete change plan).⁴ Practitioners use open-ended questions, affirmations, reflective listening, and summaries (OARS) to elicit 'change talk'—statements favoring change—while softening 'sustain talk.' The method deliberately avoids argumentation and direct persuasion, instead guiding clients to resolve ambivalence themselves.⁵

Over 200 randomized trials have tested MI across substance use, smoking cessation, medication adherence, diet, and exercise, with meta-analyses showing modest but significant effects, particularly when delivered in brief sessions and in non-English-speaking contexts.⁶ MI is effective in primary care, emergency departments, and mental health settings. It is also adapted for group formats and digital delivery, though effect sizes vary by population and fidelity.⁷

MI's philosophical roots trace to Carl Rogers's client-centered therapy, but Miller added a directive element that distinguishes it. A lesser-known variant, 'motivational enhancement therapy' (MET), combines MI with personalized feedback and was tested in Project MATCH.⁸ MI has been applied to veterinary medicine, dental hygiene, and even conservation behaviors. Training often uses the Motivational Interviewing Treatment Integrity (MITI) code to assess fidelity. Critics note that MI's mechanisms are not fully understood, and some studies show no advantage over other active treatments, prompting calls for more rigorous trials.⁶

Ambivalence

Simultaneous conflicting feelings or thoughts about change.

Change talk

Client statements expressing desire, ability, reasons, or need for change.

Sustain talk

Client statements arguing against change or maintaining the status quo.

OARS

Acronym for open questions, affirmations, reflections, and summaries.

Spirit of MI

The underlying interpersonal style: partnership, acceptance, compassion, evocation.