Project Summary The objective of the proposed study is to examine the bidirectional associations between alcohol use and intimate partner violence (IPV) during the developmental period from adolescence to young adulthood, when both alcohol use and IPV peak. Furthermore, the developmental period from adolescence to young adulthood often brings mental health challenges, such as symptoms of depression and post-traumatic stress, which can coincide with alcohol use and IPV. Thus, the present study aims to investigate the bidirectional associations between alcohol use and IPV across eleven years from adolescence (age 15) to young adulthood (age 26), and whether symptoms of depression and post-traumatic stress moderate the relationship between alcohol use and IPV. To date, studies examining the bidirectional associations between alcohol use and IPV have not been situated during this critical developmental period. Therefore, the current proposal can provide critical information on timing and vulnerability factors (e.g., depression or post-traumatic stress symptoms) to inform alcohol-related IPV prevention and intervention efforts. Furthermore, research is lacking on how the relationship between alcohol use and IPV may differ as a function of sex assigned at birth, race, and ethnicity, despite some evidence that patterns of alcohol use and IPV differ amongst these groups. Thus, the current proposal will explore differences in the relationship between alcohol use and IPV as a function of intersecting demographic identities. This project will inform future research aimed at designing culturally-affirming IPV prevention and intervention programs.