The prevalence of assaultive traumas (physical, sexual, and witnessed violence) before age 18 among all youth in COGA was higher, at nearly 78%, than comparable national surveys. For instance, the National Comorbidity Survey-Replication (Adolescent Supplement) found that 61.8% of adolescents age 12–17 had experienced a traumatic event (McLaughlin et al., 2013). The majority of youth in our sample had already experienced a serious traumatic event by age 12—median ages were 11.5 for physical assault, 12 for sexual assault, 11 for witnessed violence, and 10 for non-assaultive trauma; see Table 1 for mean ages of onset by sex and race. As in other surveys, the group most likely to experience childhood trauma were African-American youth. Black males experienced the highest rates of physical assault (13.6%) and witnessed violence (39.6%) in our sample, and Black girls experienced the highest rates of sexual assault (10.2%). Among nearly 35000 respondents in the National Epidemiologic Survey of Alcohol and Related Conditions, African Americans were more likely than Whites to have experienced child maltreatment and witnessed violence (mostly from parental IPV) (Roberts et al., 2011). Our
