Principle-Guided Psychotherapy for Children and Adolescents (FIRST): Study Protocol for a Randomized Controlled Effectiveness Trial in Outpatient Clinics.

Background: Hundreds of youth psychotherapy randomized trials have generated scores of helpful empirically supported treatments (ESTs). However, the standardized structure of many ESTs and their focus on a single disorder or homogeneous cluster of problems may not be ideal for clinically referred youths who have comorbidity and whose treatment needs may shift from week to week. This concern has prompted development of flexible transdiagnostic, modular youth psychotherapies. One of these, designed for efficient training and implementation, is FIRST-a transdiagnostic intervention built on five empirically supported principles of change (i.e., feeling calm, increasing motivation, repairing thoughts, solving problems, and trying the opposite) and targeting common internalizing and externalizing youth mental health disorders and problems. FIRST has shown promise in improving youth mental health in three open trials. Now, in a more rigorous test, we seek to (1) conduct a randomized controlled trial comparing FIRST to usual care in real-world clinical practice settings; (2) examine a promising candidate mediator of change-regulation of negative emotions; and (3) explore variables that may influence clinicians' treatment implementation. Methods: This is an assessor-naïve randomized controlled effectiveness trial in youth outpatient community clinics in New England and Texas. Using double randomization, clinic-employed clinicians and treatment-referred youths (7-15 years old) are independently randomly allocated (1:1) to FIRST or usual care. We aim to recruit 212 youth participants, all referred through normal community pathways, with elevated symptoms of anxiety, depression, conduct problems, or post-traumatic stress. This study will test the effectiveness of FIRST compared to usual care on mental health outcomes, examine whether those outcomes are mediated by regulation of negative emotions, and explore clinician factors that may be associated with FIRST implementation and outcomes. Session recordings are coded to assess treatment fidelity. Discussion: This study will evaluate the effectiveness of FIRST in youth community mental health settings, relative to the care usually provided in those settings. If FIRST is found to be effective, it could offer an efficient and practical method to increase use of empirically supported treatment principles in real-world practice contexts. Trial registration: NIH Clinical Trials Registry, NCT04725721. Registered 27 January 2021, https://clinicaltrials.gov/ct2/show/study/NCT04725721.