PROJECT SUMMARY While opioid use in the general population has received significant media and scholarly attention in recent years, very little research exists on opioid use among youth experiencing homelessness (YEH), despite nearly 70% of these youth meeting criteria for illicit drug or alcohol use disorders (SUD), and drug overdose and suicide being the leading causes of death. Our UG3/UH3 Heal Initiative study is the first to test whether a “housing first” (HF) intervention can reduce opioid use among YEH. Specifically, the ongoing UH3 phase of the “Housing, Opportu- nities, Motivation and Engagement” (HOME) study is randomizing 240 YEH ages 18-24 at high risk for opioid use disorder (OUD) to housing + opioid and related risk prevention services (n=120), or opioid and related risk prevention services alone (n=120). However, HF implementation is challenging on scale because justice system involvement often prevents or delays housing acquisition for YEH. In the increasingly tight housing market, land- lord barriers to housing YEH with criminal justice involvement (CJI) present numerous obstacles to the imple- mentation of HF (e.g., criminal background checks to screen out applicants with prior CJI, unwillingness to ap- prove applications or rent to individuals with a CJI record) and have delayed HF for youth with CJI. Consistent with NIDA's interest in supporting additional justice measures for existing awards (NOT-DA-23-011), we will capitalize on a unique opportunity to add a mixed-methods study focused on exploring the role of CJI in the HOME trial. Specifically, we will first collect new in-depth qualitative interview data from key stakeholders (land- lords, advocates, and YEH) to explore the contextual determinants (i.e., barriers and facilitators) related to the implementation of HF for YEH with CJI. This new data will provide first insights, including how specific types of CJI (e.g., number of incidents and types including incarceration, probation, warrants) influence HF participation and housing decisions, why landlords did and did not rent to YEH with CJI, and what various incentives and methods (e.g., increased deposits, rental vouchers, damage protection) could overcome the barriers to imple- menting HF with YEH with CJI. Next, we will complete supplemental quantitative analyses of new variables related to prior CJI and delayed time to housing acquisition to test the effect of CJI on main study outcomes. Our central hypotheses, based on prior literature among HF programs for adults, are that the HF intervention will have differential effects for YEH with and without CJI and that housing delays may worsen outcomes. Our results will contribute to a better understanding of barriers and facilitators of HF implementation for YEH with CJI, as well as the effects of CJI on outcomes of HF interventions among YEH. Our results will have significant impact on reducing opioid use and OUD and preventing loss of life, given the burden of OUD and high risk for opioid overdose in this population and their heightened risk for experiencing longer periods of homelessness.

PROJECT NARRATIVE Resolution of homelessness through housing and prevention services, often referred to as “housing first (HF)”, as tested in the parent study, has great potential to reduce the likelihood for the development of an opioid use disorder (OUD), continued homelessness, and other problem behaviors among youth experiencing homeless- ness (YEH). However, the implementation of HF is challenging on scale because criminal justice system involve- ment (CJI) is common among YEH and often prevents or delays housing acquisition. This administrative sup- plement will capitalize on a unique opportunity to add a mixed-methods study focused on exploring the role of CJI in the parent study's HF intervention and will inform effective strategies for implementation and sustainability, ultimately reducing risks for opioid use and premature mortality among YEH with prior CJI.