Efficacy of a Personalized, Response-based Transdiagnostic Intervention for Emotional Disorders Delivered Via the Internet: A Protocol for an Adaptive Trial

This adaptive randomized controlled trial evaluates the efficacy of a transdiagnostic, internet-delivered psychological intervention for emotional disorders, tailored to patient´s early clinical response. 366 adults with clinically significant symptoms of depression and/or anxiety will begin a 12 module self-applied program. Based on sympron reduction after the first three modules, participants will be classified as early or late responders and randomized into different experimental arms. The main hypothesis is that a hybrid format (self-applied modules plus synchronous sessions with a therapist) will yield better outcomes for late responders. Outcomes include symptom reduction, emotional regulation and internet based therapheutic alliance.

To assess its effectiveness, two formats will be compared: the original, consisting of 12 self-administered modules, and a hybrid format, which includes two synchronous sessions with a trained therapist. Early responders will either continue with the original intervention or discontinue treatment; while late responders will receive the hybrid format or continue with the original intervention. The primary expected result is that the hybrid format will improve treatment outcomes for late responders compared to the self-applied format. The findings are expected to inform clinical practice by highlighting the importance of assessing symptomatic response throughout treatment, especially in its early phases