The Impact of Motivational Interviewing on Client Response to the Treatment Rationale Within Cognitive Behavioral Therapy for Generalized Anxiety

Motivational Interviewing (MI) has been applied to the treatment of anxiety disorders in an effort to bolster engagement with and response rates to Cognitive Behavioral Therapy (CBT). Although the addition of MI to CBT has been widely advocated, little is known about the impact of MI on therapy process in CBT. The current study used the Structural Analysis of Social Behaviour (SASB) coding system to discern interpersonal processes (i.e., therapist-client interactions) within therapy sessions from an existing dataset of a clinical trial of MI plus CBT for Generalized Anxiety Disorder (GAD). The outcome data from the trial demonstrated that the addition of MI significantly improved response to CBT, specifically for those of the highest worry severity at baseline. The current study systematically examined the impact of having received MI (or not) on interpersonal processes following the presentation of the treatment rationale in the first session of CBT, a theoretically meaningful point in the CBT treatment process. In particular, SASB was employed to code 20 video-taped sessions for clients of high worry severity who either received MI as a pre-treatment to CBT (n=10) or who did not receive MI prior to CBT (n=10). MI has been found to decrease client resistance and increase client engagement and motivation for therapy in previous studies. Therefore, it was expected that those who received MI prior to CBT would be more receptive to the CBT treatment rationale and would engage in more affiliative interpersonal processes. Findings revealed that, following the presentation of the CBT treatment rationale, clients who did not receive MI prior to CBT both separated from the therapist and deferred significantly more to the therapist than those who received MI prior to CBT. Moreover, these clients shifted the focus away from themselves and onto the therapist at significantly higher rates than clients who received MI prior to CBT. Accordingly, therapists of clients who did not receive MI both shifted the focus away from the client and onto themselves at significantly higher rates than the MI group, and also engaged in more controlling behaviour than therapists of clients who received MI. These findings have significant implications for improving processes within CBT at theoretically meaningful moments in therapy.