Opioid Use Disorder Pharmaceutical Treatments: Investigating a Model and Measure of Intervention Stigma toward Medication (OPTIMISM) - Project Summary/Abstract Medication for Opioid Use Disorder (MOUD) is an effective but underused treatment for Opioid Use Disorder (OUD), reducing drug use and mortality at rates far superior to any other treatment modality. Current approved medications include methadone (a full opioid agonist), buprenorphine (a partial agonist), and naltrexone (an opioid antagonist). Despite its efficacy, MOUD remains heavily stigmatized by decision makers, healthcare personnel, and members of the general public (i.e., three stigma actor groups), with potential for differential endorsement and experience of stigma based on lived experience of OUD and racial identity. Existing qualitative research suggests this form of Intervention Stigma, manifesting both as negative attitudes (e.g., “it’s replacing one addiction for another,” “it’s not ‘real recovery,’”) as well as actions (e.g., prohibitions on MOUD in residential environments, poor reimbursement in medical settings) are driven by beliefs regarding the following domains: 1) MOUD’s differing pharmacological properties (opioid agonists, partial agonists, and antagonists), 2) prioritization of psychosocial interventions over medication, 3) regulatory and administrative burdens, 4) the value of experiential knowledge and professional anecdote over scientific research or client experience, and 5) suspicion of profit motives associated with MOUD. Evidence also suggests there is a sixth domain, risk of MOUD diversion (selling and sharing medications), influencing Intervention Stigma. Though qualitative work helps illuminate the sub-constructs of Intervention Stigma, there remains no comprehensive model or quantitative measure of Intervention Stigma for use in academic or clinical settings which captures the nuance of stigmatizing attitudes and actions across stigma actor groups, subpopulations, domains, routes of administration (injection vs. oral), and the three medication types. The proposed study aims to develop a dimensional model of Intervention Stigma by leveraging strong, statewide and national collaborations to engage with subject matter experts through the validated delphi and cognitive interviewing techniques to test and refine domains of interest and specific items. Following the establishment of the comprehensive model, the research team will develop and test an Intervention Stigma measure tailored for the three target actor groups and apply modern, multidimensional psychometric approaches to identify response patterns, scale structures, and establish construct and convergent validity evidence for each actor group version, using both online and in-person formats with large sample populations across diverse settings. Critically, the research team will consist of undergraduate and graduate student scholars and will build strong substance use focused research and training infrastructure within the Department of Psychological Sciences at the University of Missouri, St. Louis. The long-term goal of this project is to inform effective, tailored, stigma-reducing interventions, thus decreasing system- and individual-level barriers to this life-saving intervention while strengthening the research acumen of future addiction scientists.