PROJECT SUMMARY/ABSTRACT In partnership with Deaf-owned agency National Deaf Therapy (NDT), we propose the first-ever full-scale psychotherapy trial conducted in the Deaf community. The U.S. Deaf community – more than 500,000 Americans who communicate using American Sign Language (ASL) – experiences nearly triple the rate of lifetime problem drinking compared to the general population and twice the rate of trauma exposure. Hearing individuals have access to several validated treatments for comorbid alcohol use disorder (AUD) and trauma; yet there are no evidence-based treatments to treat any behavioral health condition with Deaf clients. Available behavioral health treatments fail to meet Deaf clients’ unique language access needs. Deaf people’s median English literacy level falls at the fourth grade and health-related vocabulary parallels non-English- speaking U.S. immigrants. Leveraging extensive community engagement to address these barriers, the PI’s team of Deaf and hearing researchers, clinicians, filmmakers, actors, artists, and Deaf people with AUD/PTSD developed and pilot tested Signs of Safety, a Deaf-accessible toolkit to be used with the Seeking Safety treatment protocol. The Signs of Safety toolkit provides a supplemental therapist guide and population-specific client materials (e.g., visual handouts, filmed ASL teaching stories) to meet Deaf clients’ language needs. Preliminary data from the Signs of Safety single-arm pilot and randomized feasibility pilot showed reductions in alcohol use frequency and PTSD severity from baseline to follow-up. The delivery of the experimental intervention was deemed feasible by study therapists and was well-received by participants, especially when moved to a virtual platform in response to the COVID-19 pandemic – an acceleration of the inevitable development needed to scale Signs of Safety to a national level for the proposed clinical trial. Leveraging the existing infrastructure and robust referral network of NDT, we will enroll 144 Deaf adults with past-month PTSD and problem drinking into a national, full-scale, virtual clinical trial comparing (1) Signs of Safety with (2) treatment as usual and (3) a no treatment control. Primary clinical outcomes at immediate post- treatment and post-treatment follow-up are past 30-day alcohol use frequency/quantity (Alcohol Timeline Followback) and past 30-day PTSD severity (PTSD Checklist for DSM-5). Assessment will occur at baseline, mid-treatment, immediate post-treatment, three-month post-treatment follow-up, and six-month post-treatment follow-up. Additionally, we will analyze potential moderators and mediators that lead to positive outcome, including coping self-efficacy, self-compassion, motivation for treatment, and access to health information. Our proposed aims build on eight years of KL2 and R34 empirical work, moving this program of research from Stage IB (two-arm feasibility and pilot testing) to Stage II/III (real world efficacy). The proposed R...