Genetic and environmental covariance and correlation matrices are shown in Table 5. Significant genetic correlations were found between the three externalizing behaviors (rG(HYP/IMP-INATT) = 0.5257; rG(HYP/IMP-CDP) = 0.3145; rG(INATT-CDP) = 0.3039), suggesting that these behaviors are due, in part, to the same genetic influences. However, in these adolescent females, there was no significant correlation between ADHD behaviors (HYP/IMP and INATT) and alcohol problems. Conduct problems were significantly correlated with AlcProb; however, this association was not due to genetic factors (rG = .0030), but rather to environmental contributions (rC = .4904 and rE = .1235). This finding is consistent with Rose et al (2004) and suggests that, in adolescence, correlated liabilities for conduct and alcohol problems are found in environmental factors common to both phenotypes.
