PROJECT SUMMARY/ABSTRACT Young adulthood is a critical time period in which alcohol use is common and consequential. Social media has emerged as a novel research tool to understand alcohol cognitions and behavior in this age group. The vast majority of young adults use social media, and studies have illustrated that alcohol posts are frequent and have positive associations with alcohol behavior. Previous studies have focused on two types of alcohol posts on social media: general alcohol use and intoxication/problem drinking. This study proposes to focus on a novel type of social media message, posts promoting safety, abstinence or moderation (SAM). Our previous study of college students found that SAM posts represented less than 1% of all alcohol posts; however, our newer R34 study of community college students found approximately 5% of alcohol posts represented SAM. There are two unique possibilities for SAM posts; one is that they may influence social norms about alcohol use via social media’s broad reach and influence. Second is these posts may be displayed by individuals who are considering behavior change, an ideal population for targeted interventions. To date, no studies have examined the prevalence, content and meaning of SAM posts across a diverse population of young adults. Our over-arching goal is to use social media to identify problem alcohol use in young adults and provide feasible, scalable and targeted interventions. We have pursued this goal over the past decade, including a recently completed NIAAA- funded R34 (MPIs Moreno and Lewis, R34AA025159) to identity at-risk community college students using Facebook and Instagram and provide a validated web-BASICS intervention. This R21 proposal would advance the field by understanding the frequency and meaning of SAM posts. We will utilize Qualtrics to recruit a diverse young adult sample (n=300). Eligible participants will maintain at least one social media profile from among profiles with high identity affordances, including Instagram, Twitter and Facebook. After obtaining consent and completion of an online survey, we will link to up to three of participants’ social media profiles. For Aim 1, we will use content analysis to evaluate up to 3 social media profiles over one year for each participant. Coders will evaluate displayed alcohol posts and SAM posts. Aim 2: We will use Qualtrics survey data from all participants to assess how alcohol and SAM posts are associated with protective behavior strategies, alcohol behavior and social norms. Aim 3: After Aims 1 and 2 analyses are complete, we will select 25 participants who displayed SAM posts and conduct cognitive interviews to understand how they perceive SAM posts. Consistent with the R21 mechanism, this study would provide fundamental knowledge to understand the frequency and meaning of SAM posts. The outcomes of this innovative study will inform novel opportunities for social media messaging, big data surveillance approaches and ta...