Challenges using motivational interviewing as an adjunct to exposure therapy for obsessive-compulsive disorder.

Exposure and response prevention (EX/RP) is an efficacious treatment for obsessive-compulsive disorder (OCD). However, patients often do not adhere fully to EX/RP procedures. Motivational interviewing (MI) has been shown to improve treatment adherence in other disorders. This pilot study used a randomized controlled design to examine whether MI can be successfully added to EX/RP and whether this intervention (EX/RP+MI) could improve patient adherence to between-session EX/RP procedures relative to EX/RP alone. Thirty adults with OCD were randomized to 18 sessions of EX/RP or EX/RP+MI. Therapists rated patient adherence at each exposure session. Independent evaluators assessed change in OCD and depressive symptoms, and patients completed self-report measures of readiness for change and quality of life. The two treatment conditions differed in degree of congruence with MI but not in conduct of EX/RP procedures. Both groups experienced clinically significant improvement in OCD symptoms, without significant group differences in patient adherence. There are several possible reasons why EX/RP+MI had no effect on patient adherence compared to standard EX/RP, each of which has important implications for the design of future MI studies in OCD. We recommend that MI be further evaluated in OCD by exploring alternative modes of delivery and by focusing on patients less ready for change than the current sample.