Community health worker implementation of transdiagnostic evidence-based treatment in Spanish: protocol for refinement, implementation, and a feasibility pilot RCT

Latine people in the U.S. face unequal access to mental healthcare, particularly families and parents with limited English proficiency. Community health workers (CHWs) are well-positioned to increase access to care if integrated into mental health services. The Common Elements Treatment Approach (CETA) is a transdiagnostic evidence-based treatment (EBT) designed to be delivered by lay providers with little to no prior mental health training (i.e., CHWs). CHWs have demonstrated effectiveness in delivering CETA and other EBTs globally; however, there is limited evidence to guide domestic implementation of these models. This study aims to evaluate the implementation of CHW-delivered CETA with Spanish-speaking Latine parents to establish initial feasibility and proof of concept prior to expanding the study of CHW EBT models across other populations and settings. This protocol outlines a three phase study. Phase 1 involves collaboration with key partners to refine CETA fit for the local context using the ADAPT-ITT model, an implementation framework for EBT refinement. Phase 2 will use mixed methods to assess multilevel contextual determinants during the CETA training period, which includes initial CHW implementation with clients, and using key partner feedback for implementation planning. Phase 3 involves conducting a randomized feasibility pilot of CHW-delivered CETA in Spanish with Latine parents who will be randomized to receive CETA immediately or after a 5-month delay. Key outcomes will include administrative data (i.e., patient attendance and retention over the course of the intervention), patient-report data (i.e., implementation questionnaire, validated mental health symptom measures pre-, during-, and post-intervention), provider-report data (i.e., fidelity, implementation questionnaire), and qualitative interviews to evaluate feasibility, acceptability, and preliminary effectiveness of CHW-delivered CETA. This study stands to have a significant public health impact by advancing an innovative mental health model, i.e., CHW-delivered EBTs, that has great potential for expanding mental health service access for marginalized families who are underserved in traditional models of care. This project begins with one population (Spanish-speaking Latine parents) to establish initial feasibility and proof of concept prior to expanding the study of these models to other diverse populations and settings. Prospectively registered on February 4, 2026, at ClinicalTrials.gov no. NCT07390630.