Improving Brief Assessment of Suicidal Thoughts and Behaviors in Youth: An Engaged, Stakeholder-Informed Approach to Measure Development, Testing, and Implementation - PROJECT SUMMARY/ABSTRACT Suicide is the third leading cause of death among youth ages 15-24 in the United States. Accurate assessment of suicidal thoughts and behaviors (STBs) is critical in research and clinical practice. Brief assessments (e.g., single items) are necessary for feasibility in many contexts, but little work has focused on validating brief STB assessments, and extant research has documented wide discrepancies in reports of STBs across measures. Invalid STB assessments have profound implications for development of suicide theories, research on suicide risk and protective factors, and clinical management of STBs, ultimately hampering suicide prevention. Despite the challenges of STB assessment, single-item measures can have adequate psychometric properties, comparable to their multi-item counterparts. Psychometric validation and standardization of STB measures will improve replicability of research findings and facilitate accurate identification of STBs in risk assessment, which is critical to management and prevention of STBs. The proposed study will recruit two samples of youth ages 15-24 with lived experience of STBs in order to refine single-item STB measures, test their psychometric properties, and identify other factors impacting response accuracy. Toward the long-term objective of improving prevention of suicidal thoughts and behaviors in youth, this study has 3 specific aims: (1) develop a pool of clear, interpretable items to assess youths’ experiences with STBs using cognitive interviewing, (2) examine psychometric properties of the resulting set of single-item STB measures, and (3) identify factors that impact responses beyond item interpretation through an implementation science framework. The proposed research and training activities will be conducted at Texas Tech University. This fellowship will provide specialized training necessary for the applicant to become an impactful independent clinical scientist. Training will focus on three goals: (1) enhance knowledge of youth STBs and research best practices with youth through regular mentor meetings, lab meetings, guided readings, and attendance at youth advisory board meetings and relevant conferences, (2) gain expertise in cognitive interviewing and other qualitative research methods through formal courses and workshops, regular mentor meetings, guided readings, and lab meetings, guided applied practice, and collaborating on projects using existing cognitive interview data, and (3) gain expertise in stakeholder-centered approaches to designing and implementing suicide-focused research with youth using dissemination and implementation science principles through guided readings, lab meetings, regular mentor meetings, attending workshops, and guided applied practice. Results of this study will provide actionable recommendations for brief assessment of STBs, improving management of risk and data collection accuracy for STBs assessed in research and clinical contexts.