Trauma is a transdiagnostic risk factor for posttraumatic stress disorder (PTSD), major depressive disorder (MDD), increased alcohol use, and alcohol use disorder. Additionally, these conditions tend to co-occur, and are genetically-influenced. Decades of work has emphasized the importance of count, type, and timing of traumatic events on these mental health outcomes. However, most work has not examined these mental health conditions simultaneously and very few have investigated their effects over the course of development. This proposed study will examine the role of trauma characteristics on these outcomes across childhood into adulthood, via the use of multiple longitudinal datasets--ALSPAC, as well as two others (Add Health, a nationally representative sample, and ABCD, a diverse sample of children aged 9-10 across the US). This study will also use cutting edge genetic methods (genomic structural equation modeling-derived polygenic risk scores/PRSs) to examine the genetic influences on these conditions, as well as investigate potential interactions between genetic risk and trauma characteristics.