The Relationship Between Historical Trauma, Substance Use, and Suicidal Ideation in Native Hawaiian/Pacific Islander Adults: A Mixed-Methods Approach - Project Summary/Abstract Research targeting substance use and its comorbidities in Native Hawaiian/Pacific Islander (NHPI) communities often focuses on youth participants or aggregates small samples of NHPIs with the data of Asian Americans. This has created a significant gap in the field’s understanding of substance use and suicidal ideation in this underserved population. Further, NHPI advocacy groups cite both substance use and historical trauma as primary targets for research. Therefore, the specific aims of this project are to (1) conduct qualitative focus groups to understand the relationships between substance use, suicidal ideation, and historical trauma in NHPI adults and (2) conduct a subsequent quantitative analysis to develop a model of these associations. This project is significant because we will be building the first model of substance use and suicidal ideation in NHPI adults, a community that has been largely underserved by academic research. This project is innovative because it will utilize a mixed-methods research design with community based participatory research principles, including the formation of a NHPI community advisory board, to inform this model. The proposed study will be completed over the course of two years and two studies; the first is qualitative, the second quantitative. Study 1 will conduct 3–5 focus groups with 4–8 NHPI adults per group (n = 20–30) who will explore the impact of historical trauma on substance use and suicidal ideation using semi-structured interviews that will mirror traditional NHPI talking circles. Study 2 will translate the themes revealed in the qualitative analysis from Study 1 to inform measure selection in a quantitative analysis, with the goal of testing a model of the relationships between historical trauma, substance use, and suicidal ideation in NHPI adults (n = 120–168). Findings will be among the first to conceptualize these relationships in NHPI adults, where research is desperately needed. This project is aligned with NIDA’s 2022-2026 Strategic Plan as it explores the social and contextual factors that manifest and maintain substance use behavior by exploring comorbidities and improving the implementation of evidence-based practice for clinicians who seek to reduce substance use in NHPI communities through the development of the model. Further, this project will provide the Principal Investigator with the grantsmanship, networking, and methodological tools to establish a career serving the needs of NHPI communities. The research environment at University of Rhode Island including office space, technology, and grant support, along with excellent sponsors and consultants with expertise in relevant content areas and mixed methodology research, provide the ideal setting and mentorship to successfully conduct the proposed project. This project will create vital research training opportunities for the applicant’s future career as an independent researcher working within NHPI communities to alleviate health disparities, a role which is necessary for improved health among this population.