Building the foundation: Training, stakeholder engagement, and planning for Common Elements Treatment Approach (CETA) implementation in Uganda.

Early and ongoing stakeholder engagement is critical to the development and implementation of scalable behavioral health interventions. Our overarching goal in this implementation research study was to understand and document the process of planning and rolling out Common Elements Treatment Approach (CETA), a transdiagnostic mental health intervention, in Uganda. Guided by the Consolidated Framework for Implementation Research (CFIR) 2.0, we conducted in-depth interviews with multilevel stakeholders (healthcare providers, MOH members, clinic managers, implementing partners, n = 20) to understand and document the process of planning and rolling out CETA in Western Uganda. All interviews were audio recorded, transcribed, and analyzed thematically in Dedoose using a codebook based on CFIR 2.0 domains and constructs. Multilevel stakeholder engagement supported strategic decision making at each stage. Early endorsement of CETA by Uganda's MOH was instrumental in facilitating program integration. Ministry of Health leadership guided facility selection, while clinic leaders identified trainees positioned to implement CETA. Training incorporated both didactic and participatory methods, including real-time adaptation of intervention content for contextual relevance and identification of "champion" trainees to serve as supervisors as part of the ongoing support supervision infrastructure. During rollout, an incremental implementation strategy facilitated integration into clinic workflows. Ongoing multilevel stakeholder supervision and technical assistance helped CETA deliverers troubleshoot challenges, maintain fidelity, and gain confidence. Together, these processes enabled expansion beyond the initial pilot sites, providing early evidence of stakeholder-perceived feasibility and identifying foundational conditions for scalability. Continued engagement with policymakers, those delivering CETA, and community stakeholders will be essential to refine CETA implementation and support integration into national mental health strategies. By reframing stakeholder engagement as an implementation strategy that builds enduring, locally led infrastructures, this study offers a replicable model for preparing behavioral health interventions for scale-up in low resource settings and advances implementation research in global mental health.