Introduction A trauma-informed approach (TIA) means working with awareness that people's histories of trauma may shape the way the engage with a services, organisations or institutions. Young people with childhood adversities may be at risk of re-traumatisation by organisational practices in schools, universities, and by employers and health agencies when they seek support. There are limited evidence-based resources to help people working in diverse public sector to work with adolescents in trauma-informed ways and the needs of adolescents have not been central in their development. This study contributes to public sector capacity to work in trauma-informed ways with adolescents by co-designing and evaluating the implementation of a youth-informed organisational resource. Methods and analysis This is an Accelerated Experience-based Co-design (EBCD) study followed by a pre-post evaluation. Public sector organisations or services, and adolescents connected with them, will collaboratively reflect on lived experience data assembled through creative arts practice, alongside data from epidemiological national datasets. These will present knowledge about the impact of adverse childhood experiences on adolescents mental health (Stage 1). Collaboratively, priorities (touch points) for organisational responses will be identified (stage 2), and a low-burden resource will be co-designed (stage 3), and offered for implementation in diverse settings (stage 4) and evaluated (stage 5). This will provide insights into what adolescents and public sector organisations in the UK want from a TIA resource, the experience of organisations in implementing this and recommendations for resource development and implementation. Ethics. The UK National Health Service Health Research Authority approved this study (23/WM/0105). Knowledge products will include website detailing the created resource and a youth-created film documenting the study process, the elements of the co-designed resource, and experiences of implementation. Dissemination will target academic, healthcare, education, social care, third- sector, local government settings via knowledge exchange events, accessible briefings and publication.

The authors have declared no competing interest.

This work was supported by the UKRI Medical Research Council. (MR/ W002183/1).

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The UK National Health Service Health Research Authority approved this study (23/WM/0105).

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