Evaluating the relative contribution of patient effort and therapist skill in integrating homework into treatment for posttraumatic stress disorder.

Objective: Homework has historically been an integral component of cognitive behavioral interventions for posttraumatic stress disorder (PTSD). Previous studies differ in the measurement of therapy homework, resulting in inconsistent conclusions about its contributions to symptom reduction. Given the methodological burden associated with examining therapist skill within sessions, there has been no research evaluating the impact of both therapist and patient efforts on homework within and outside of the therapy session across protocols.

Method: We first examined the relative contribution of four homework-related variables to treatment outcomes of survivors of interpersonal violence (12 sessions; 58 survivors) diagnosed with PTSD and treated with cognitive processing therapy (CPT) in two randomized, controlled clinical trials. We then assessed the moderating effect of therapist competency in the homework element of CPT on these associations by examining therapist skill in 544 therapy sessions scored by independent raters.

Results: Perceived helpfulness of assignments emerged as the only significant predictor of PTSD symptom reduction (β = 0.48). Therapist homework competency moderated the relationship between time spent on homework and treatment outcome, such that more time spent on homework was associated with significantly poorer treatment response at low levels of therapist homework competency.

Conclusions: Results suggest that patients' understanding of the direct contribution of homework to recovery is critical for increasing the effectiveness of the homework component of therapy. Therapist skill in incorporating homework effectively into the protocol is variable. It is essential that therapists ensure that patients' efforts (e.g., time dedicated to the task) are yielding clear results and perceived as fruitful. (PsycInfo Database Record (c) 2023 APA, all rights reserved).