The rise of co-production and transdisciplinary research aims to improve research quality and the relevance, acceptability, and accessibility of healthcare by addressing power imbalances and involving service-users. This paper focuses on the CONIFAS study, which aimed to create a nature-based intervention for children with ADHD using co-production and co-design methodologies. ADHD significantly impacts mental well-being and various life outcomes, and while nature-based interventions show promise, evidence-informed, child-centric interventions are lacking. CONIFAS prioritized equal partnership between children, families, professionals, and researchers to ensure the intervention is accessible, acceptable, and fit-for-purpose. This study builds on limited existing literature regarding co-production with children with ADHD, aiming to share experiential learning to support future research in this area.

The paper reviews literature on co-production and transdisciplinary research, highlighting the growing need for detailed sharing of best practices, particularly in healthcare. While numerous 'co-' research terms exist (co-production, co-design, etc.), clear methodological descriptions are limited. The authors cite relevant work on co-design frameworks and existing nature-based interventions for ADHD, acknowledging a lack of specific guidance on co-producing with children with ADHD. The literature emphasizes the need for child-centered interventions informed by lived experiences to enhance effectiveness and accessibility.

CONIFAS employed a co-production methodology guided by the Double Diamond model, encompassing four phases: 1. **Discover:** Workshops explored the experiences of ADHD and engagement with nature, gathering insights from professionals, children and families separately, and then together. 2. **Define:** Workshops defined the intervention's content, look, feel, and delivery based on the gathered information. 3. **Develop:** User-testing with new families assessed the prototype intervention's usability and effectiveness. 4. **Deliver:** Final workshop incorporated feedback from user testing to refine the intervention. Thirty participants (10 children, 10 parents/guardians, and 10 professionals) were involved, recruited through various channels. Workshops were held in an outdoor setting, using an iterative process where content and activities were adapted based on participant feedback. A graphic designer created visual notes, improving accessibility and transparency. The study also included 'catch-up' calls for those who missed sessions, particularly benefiting professionals with scheduling conflicts. Initially separating stakeholder groups enabled open discussions before combining perspectives in later phases.

The study successfully created a nature-based intervention for children with ADHD through co-production. Key findings highlight the importance of: * **Adequate Resources:** Appropriate remuneration, travel reimbursements, and provisions for children enhanced participation. * **Shared Power:** Although the study didn't fully achieve equal power sharing due to grant funding constraints, efforts were made to involve participants in decision-making and foster a sense of ownership. * **Valuing Diverse Knowledge:** Visual note-taking, play-based approaches, and a sticker rewards system supported inclusion and confidence, particularly for children. * **Building Trust:** Creating a supportive and flexible environment, allowing for individual needs, fostered trust among participants. * **Promoting Diversity:** While challenges in achieving diverse recruitment existed due to time and resource limitations, efforts were made to include families from various backgrounds in the user-testing phase. The study generated practical tips for future co-production projects, including flexible planning, using visual note-takers, employing strengths-based approaches, and utilizing a gentle reward system.

CONIFAS demonstrated the feasibility of co-producing a nature-based intervention for children with ADHD, highlighting the importance of a flexible, inclusive, and empowering approach. The study’s success lies in prioritizing shared power, diverse perspectives, and trust-building. The findings address the need for child-centered interventions by directly involving children and families in the design process. The practical tips provided offer valuable guidance for researchers engaging in co-production, particularly when working with neurodiverse populations. The study's limitations, such as challenges in achieving full power-sharing and diverse recruitment, offer insights for future studies.

CONIFAS successfully co-produced a nature-based intervention for children with ADHD. The study's key contribution is the shared experiential learning and practical guidance provided for future co-production research, emphasizing flexibility, inclusive methods, and the importance of valuing diverse contributions. Future research could explore the intervention's effectiveness through feasibility testing and broader implementation, while also addressing the limitations encountered regarding power-sharing and diverse recruitment.

The study's limitations include challenges in achieving full power-sharing due to pre-existing grant funding parameters and constraints on fully diverse recruitment. The small sample size of the co-production group and limited representation from specific professional groups might affect the generalizability of findings. The study's focus on a specific geographical area limits the extrapolation of results to other regions. Future research should address these limitations to ensure wider applicability and inclusivity.