The Temporal Relationships Between Therapist Adherence and Patient Outcomes in Dialectical Behavior Therapy

What is the public health significance of this article? This study highlights the importance of delivering DBT according to the manual, as this is likely to result inbetter patient outcomes. Therapists may find it easier to deliver DBT adherently to patients who are more severely impaired. Objective: Although Dialectical Behavior Therapy (DBT) is a well-established evidence-based psychotherapy, little is known about the role of therapist adherence in promoting positive outcomes. This study evaluated the temporal relationships between therapist adherence to DBT and patient outcomes, as well as potential moderators of these relationships. Method: Data were from six clinical trials conducted in research and community settings with a variety of patient populations. In these trials, trained observers rated 83 therapists for adherence during 1,262 DBT individual therapy sessions with 288 patients. Patient outcomes included suicide attempts, nonsuicidal self-injury (NSSI), treatment dropout, psychiatric hospitalizations, and global functioning. Longitudinal mixed-effects models evaluated the time-ordered, bidirectional relationships between adherence and outcomes. Results: Higher therapist adherence significantly predicted fewer subsequent suicide attempts (p = .002, eta = 0.32) and a lower risk of dropout (p = .002, eta = 0.33), and the latter relationship was strongest among patients with comorbid opioid dependence. Higher therapist adherence predicted fewer subsequent hospitalizations among community therapists (p = .001, eta = 0.35) and patients that were not exclusively suicidal/self-injuring (p < .001, eta = 0.41). Conversely, more frequent NSSI (p = .03, eta = 0.22) and worse global functioning (p = .01, eta = 0.26) predicted higher subsequent therapist adherence, and the latter relationship was moderated by patient population. Conclusions: Therapist adherence improves several key patient outcomes and retention, highlighting the importance of delivering DBT with adherence to the manual. Therapists may find it easier to deliver DBT adherently to more severely impaired patients.