Research examining the impact of therapist experience on client outcomes has yielded mixed findings. The current study aimed to improve upon previous research by examining the impact of global trainee therapists' experience, as well as treatment protocol-specific experience, on client outcomes. Data were obtained based on 319 clients being treated by 33 therapists using a 12-week transdiagnostic cognitive-behavioral group therapy specifically for anxiety disorders. Results demonstrated that clients overall showed significant improvement in self-reported anxiety and clinician severity ratings, and that the amount of therapist experience was unrelated to improvement. The current study suggests that trainee therapists' experience, whether examined as global amount of therapy experience or specific experience delivering a specific treatment protocol, was unrelated to treatment outcomes or treatment discontinuation across a range of outcomes.
Keywords: anxiety; cognitive behavior therapy; experience; training.