A behavior-analytic account of motivational interviewing.

Several published reports have now documented the clinical effectiveness of motivational interviewing (MI). Despite its effectiveness, there are no generally accepted or empirically supported theoretical accounts of its effects. The theoretical accounts that do exist are mentalistic, descriptive, and not based on empirically derived behavioral principles. Empirical research is being generated regarding the role of client and therapist verbal behavior in MI. Client and therapist speech in MI sessions has been correlated with subsequent client behavior change (Amrhein, Miller, Yahne, & Fulcher, 2003; Gaume, Gmel, & Daeppen, 2008; Moyers et al., 2007). Although provocative, these findings are correlational and no theory has yet been provided to explain them. The purposes of the present paper are (a) to bring MI to the attention of clinical behavior analysts; (b) to provide a conceptual account of MI that relies on recent developments in the behavior analysis of motivation and verbal behavior, especially stimulus equivalence and transformation of functions; (c) to provide a possible answer to two critical questions: "How does MI evoke client in-session talk abut behavior change?" and "Why is this change talk related to outcomes?"; and (d) to use this account to identify important research questions and perhaps enhance MI's effectiveness.