PROJECT SUMMARY/ABSTRACT Nearly 60% of firearm-related deaths are suicides, and over half of suicide deaths involve firearms. Further nearly half of firearm suicide decedents were intoxicated at the time of their death. Therefore, alcohol is a key modifiable risk factor for reducing firearm suicide, which is essential to ameliorating the public health crises of suicide and firearm violence. While alcohol and firearm access have been studied as distinct risk factors for suicide, the three have yet to be integrated into a single coordinated line of research that leverages multiple methods to understand their linkages. One challenge is the lethality of firearm suicide, which leaves few survivors to study. Many people contemplate firearm suicide, however, and this group provides a key opportunity to understand people who die by firearm suicide. Preliminary analyses with our existing survey data suggests about 10% of people have contemplated firearm suicide, and 7% report firearm suicidal ideation and a binge drinking episode in the last month. We also find reliable associations among past suicide attempts, current suicidal thoughts and behaviors, and alcohol use problems that varies with the ‘intensity’ of gun ownership. That is, people with more experience with firearms and who engaged in more gun carrying reported more suicidal thoughts and behaviors, with a subgroup of high-risk gun owners who exhibit numerous risk factors for firearm suicide and violence including problematic alcohol use. Further, timeline follow back studies of recent suicide attempts find the strongest risk factor is recent alcohol use. We propose three aims focused on understanding firearm suicidal ideation and the role of alcohol and firearm access. First, we will conduct a nationally representative survey using probability sampling focused on suicide risk, alcohol use problems, and firearms to test new hypotheses and provide more definitive findings on the intersection of alcohol use, firearm access, and suicide at the population level. Second, we will build on these analyses by conducting focus groups and qualitative research of people who have seriously considered suicide by firearm. We will use mixed methods to identify themes that characterize pathways to firearm suicide (as well as safety towards help seeking) with an emphasis on the role of alcohol use among people with a history of firearm suicidal ideation and problematic alcohol use. These findings will be used to design and develop content for a process-orientated study using ecological momentary assessment (EMA) to study the dynamics of firearm suicidality and alcohol use in real time. The EMA study will be conducted for 28 days among participants who report recent firearm suicidal ideation and problematic alcohol use and who own or have access to a firearm. Key goals will be to determine the variability of firearm suicidal ideation and how this covaries or is moderated by alcohol use and ease of access to firearm...