PROJECT SUMMARY/ABSTRACT: RESEARCH CORE The prevalence and incidence of mental health challenges, including addictive behaviors, continues to be sub- stantially elevated among American Indian/Alaskan Native (AI/AN) populations when compared to other racially and ethnically minoritized groups in the United States. Despite this substantial need, AI/AN communities remain underserved and often lack necessary resources for addiction treatment and prevention. To help fill these key gaps in addiction resources and training, this Research Core will evaluate a culturally grounded training curricu- lum, xaʔtus (meaning First Face) - for Mental Health. This curriculum will train tribal community members in how to respond to youth and adults experiencing mental health crises and serve as a bridge between these individuals and the help (in some cases professional) they need. The proposed evaluation of the program will use a Tribal Participatory Research (TPR) approach, working with representatives from seven tribes to ensure that the needs and goals of the tribal partners are emphasized in the research design and resulting products. To evaluate xaʔtus, the Research Core will use a randomized waitlist control design, implemented in seven tribes, that in- cludes five assessment time points for both initial trainees (n=350) and waitlist controls (n=350). These assess- ments will measure knowledge about mental health and addiction, as well as the ability and confidence of indi- viduals to respond appropriately to mental health crises. We will also evaluate the potential for community-level effects of xaʔtus with a three-wave repeated cross-sectional community survey (n=400), which will examine community-level mental health stigma, mental health and social isolation, perceived support, help-seeking activ- ities, and treatment access and utilization. We will supplement these surveys with aggregated records from be- havioral health centers in these communities (e.g., number of treatment referrals in the past year). This Research Core will provide knowledge about the extent to which this culturally appropriate training program influences mental health, community perceptions about mental health, and community mental health resource availability, both at the individual and community levels. We will share our findings with tribal councils and community mem- bers to ensure that the potential benefits of training are widely disseminated among AI/AN individuals in these communities, as well as disseminating our findings through more traditional academic means with permission from the involved tribes.