PROJECT SUMMARY Symptoms of Attention-Deficit/Hyperactivity Disorder (ADHD) emerge as early as preschool and are highly persistent throughout childhood. Early and effective treatment can blunt the typical developmental progression seen with ADHD. Despite the importance of early intervention, historically minoritized children are less likely to be identified as needing supports, and less likely to receive appropriate treatment compared to white children. This disproportionately in service delivery may place some children on negative long-term behavioral health trajectories. To reduce this dramatic disparity in ADHD that is strongly associated with the trajectory of a child’s future, it is critical that we identify malleable factors associated with eliminating ADHD disparities in preschool. For preschoolers who display elevated ADHD symptoms, behavioral interventions are recommended as the first line of treatment and are most effective when they target both parents and teachers. However, parents and teachers experience barriers to implementing behavioral interventions with the recommended frequency and fidelity with teachers frequently citing parents as barriers to adherence of behavioral interventions. In the current study, we propose that the relationship between parents and teachers is a determinant of ADHD outcomes by impacting the potency (and use) of behavioral interventions. Our overarching goal is to Discover, Design, and Test a brief intervention to improve parent and teacher engagement in behavioral interventions for preschoolers demonstrating elevated ADHD symptoms (Parent-Educator Action Response; PEAR). The project will be conducted in 3 phases: 1) discover barriers to engaging in behavioral interventions among parents and preschool educators as well as stakeholder-informed strategies to address these barriers through an Innovation Tournament (Aim 1), (2) iteratively design and build PEAR to address identified barriers from Aim 1 through a program development team and rapid prototyping (Aim 2), and (3) test the acceptability and feasibility of PEAR in small-scale randomized controlled trial of the PEAR + behavioral intervention compared to behavioral intervention only with 14 classrooms (42 parents and 14 educators of children aged 3-6 years old with elevated ADHD symptoms; Aim 3). This K23 reflects the Notices of Special Interest in Diversity (NOT-OD- 20-31), NIMH Strategic Plan Goal 3 (Strive for Prevention and Cures), and the NIMH call to prevent or forestall the emergence of ADHD in preschool (RFA-MH-21-230) by focusing on promoting parent and teacher engagement in behavioral interventions to improve implementation, ultimately improving outcomes for preschoolers from historically minoritized backgrounds with elevated ADHD symptoms. The research aims will also serve as vehicles for pragmatic learning of the following training goals: 1) culturally humility, 2) expertise in intervention development to reduce disparities, 3) advanced s...