Strengthening Prevention Systems: Insights from Two Decades of Researcher-State Agency Partnership to Evaluate Youth Substance Use Prevention in Washington State.

Despite decades of investment in evidence-based prevention, translating research into sustained, contextually relevant practices within communities remain a challenge. Research-practice partnerships (RPPs) offer a promising model for bridging this gap through structured, long-term collaborations grounded in shared goals and mutual benefit. This manuscript presents a case study of a two-decade partnership between Washington State University's IMPACT Research Lab and the Washington State Health Care Authority's Division of Behavioral Health and Recovery. We describe the history, evolution, structure, and key elements contributing to the partnership's success. To illustrate the empirical value and impact of this partnership, we present cross-sectional findings from two complementary evaluation efforts focused on the Community Prevention and Wellness Initiative (CPWI), a strategic, data-informed, community coalition-based framework that brings together key local partners to provide evidence-based substance use prevention programs. The Developmental Trend Evaluation assessed the effects of CPWI on developmentally expected patterns of changes in adolescent substance use and related risk factors. Results suggest that CPWI is associated with slower increases in substance use over time compared to comparison communities. The RE-AIM evaluation highlights CPWI's public health impact across five dimensions: reach, effectiveness, adoption, implementation, and maintenance. Findings from these evaluations have informed statewide funding and strategic planning decisions. We also discuss challenges faced by our partnership and the adaptive strategies we have used. This manuscript contributes to the growing RPP literature on behavioral health prevention, demonstrating how sustained researcher-state agency partnership can strengthen prevention systems, inform policy, and promote the well-being of youth, families, and communities.