How important is the therapeutic alliance in treating obsessive-compulsive disorder with exposure and response prevention? An empirical report

Objective: Substantial research has established exposure and response prevention (EX/RP) as an effective treatment for obsessive-compulsive disorder (OCD). Yet, the role of the therapeutic alliance as a factor in EX/RP remains a relatively understudied area. We sought to investigate this issue and explore which aspects of the alliance matter most to treatment outcome. Method: Data came from 37 adult OCD patients who completed 17 sessions of manualized EX/RP as part of a randomized controlled trial of SRI augmentation. Patients rated the therapeutic alliance at the third therapy session using the Working Alliance Inventory-Short form (WAI-SF), which includes three subscales to rate alliance dimensions (Goal, Task, and Bond) as well as a total score reflecting the overall strength of the working alliance. OCD symptoms were rated at baseline and post-treatment using the Yale-Brown Obsessive-Compulsive Scale (YBOCS). In addition, therapists rated the degree to which patients adhered to between session EX/RP assignments. Results: Adjusting for baseline severity, total score on the WAI-SF did not significantly predict post-treatment YBOCS. Follow-up analyses revealed that higher scores on the Task subscale were significantly associated with lower post-treatment severity. Scores on the Task subscale also predicted degree of patient adherence to between session EX/ RP assignments, which mediated the relationship between task alliance and treatment outcome. Conclusions: Although overall ratings of the quality of the therapeutic alliance were not related to EX/RP outcomes, the degree to which patients and therapists allied on the tasks of therapy did predict outcomes, suggesting that this particular aspect of the therapeutic alliance matters most to EX/RP outcomes. Better agreement on the tasks of therapy also related to better EX/RP adherence, which mediated treatment outcome. Limitations and clinical implications are discussed.