How is motivational interviewing (un)related to self-determination theory: An empirical study from different healthcare settings.

To explore how quality aspects and clients' verbal behaviors in Motivational Interviewing sessions correspond with counsellors' support of basic psychological needs described in Self-determination Theory, we conducted a mixed method study with quantitative analyses of transformed qualitative data from counselling sessions. Coding manuals identified if the counselling was consistent with Motivational Interviewing and the support of basic psychological needs. The study supported a conceptual relationship between motivational interviewing (MI) and self-determination theory (SDT), except for autonomy support which was conceptualized differently in the two approaches. Relational support in SDT and MI were closely linked to each other and were also strongly related to other MI-congruent and promotive counselors' verbal behavior. Client amotivation in SDT and change talk in MI were negatively correlated, and clients' autonomous motivation in SDT was related to change talk in MI. Counselors emphasized relational support, using decisional balance comprehensively, but offered competence support less often. The counseling was, however, sensitive to the clients' motivational regulation of behavior change.