Prior studies have shown that exposure to childhood maltreatment is strongly correlated with and predictive of cannabis initiation and progression to problem use. Building upon this prior research, we employed a genetically informative design to estimate the extent to which genetic and environmental factors contribute to this correlation in African-American (AA) and European-American (EA) young women. We extended our understanding of this association in four ways. First, at the phenotypic level, we found childhood maltreatment was associated with greater likelihood of cannabis initiation before age 15 among both EAs and AAs but later initiation only among EAs, and with approximately twofold greater risk of cannabis problems in both racial/ethnic groups. Second, in examining familial influences, we found that whereas childhood maltreatment could be attributed in large part to shared environment (C) in both EAs and AAs, genetic influences (A) accounted for a much greater proportion of variance in cannabis outcomes. Thus, there was no evidence for genetic sources contributing to overlap between maltreatment and cannabis involvement (i.e., gene – environment correlation). Third, we found evidence of racial/ethnic differences in the
