The present analyses show that the presence of childhood Conduct Disorder increases the risk for young adult SUD in offspring of female alcoholics, a relationship previously reported for offspring of male alcoholics (Schuckit et al (2008). Similarly, presence of ADHD in childhood increased the likelihood of having a SUD diagnosis by young adulthood. Whether the presence of externalizing disorders of childhood and adolescence sets the stage for later development of SUD through increased exposure to peers with similar problems and predilection for substance use is unknown. It is also possible that externalizing disorders of childhood are one pleiotropic manifestation of a genetic predisposition to SUD that is expressed in an alternate manner in childhood and adolescence. In comparison to other childhood behavioral disorders, Conduct Disorder is one of the most powerful predictors of SUD (Ohannessian et al., 1995) and has been reported to be a better predictor of SUD outcome than having a family history of psychopathology, having divorced parents, or family income (Schuckit et al 2008). Two studies have reported that presence of either Oppositional Defiant Disorder or Conduct
