Exploring change in cognitive-behavioral therapy for generalized anxiety disorder: A two-arms ABAB crossed-therapist randomized clinical implementation trial

OBJECTIVE: There is little evidence-based knowledge of how psychotherapists should handle both sudden gains and more gradual session-by-session changes, either in general or in individuals suffering from generalized anxiety disorder. METHODS: Using an ABAB crossed-therapist randomized clinical implementation trial design (N = 80 patients and 20 therapists), we contrasted a Prolonged Focus on Change (PFC, N = 40) implementation with a State-Of-The-Art (SOTA, N = 40) implementation. Both implementations were based on a widely used cognitive behavioral therapy approach (Mastery of your Anxiety and Worry package) with the only difference that in the PFC implementation, the therapists were instructed to systematically explore eventual changes at the beginning of the therapy sessions. RESULTS: Based on a 3-level hierarchical linear model, PFC implementation showed faster symptom reduction in worry over therapy (i.e., linear change) and a decelerated (quadratic) change until 12-month follow-up in comparison to the SOTA implementation. CONCLUSION: These findings provide clinically useful information about potential short-term and long-term effects of exploring occurring change in GAD populations. Randomized clinical implementation trial designs are a step forward allowing to experimentally investigate basic psychotherapeutic strategies in process-based psychotherapy. (PsycInfo Database Record (c) 2021 APA, all rights reserved)