alcohol involvement, including heavier drinking, DUIs (Hingson et al., 2001; Hingson et al., 2002; Hingson et al., 2000; Hingson et al., 2004; Hingson et al., 2006; Hingson et al., 2008; Lynskey et al., 2007) and importantly, alcohol dependence (Chou and Pickering, 1992; Dawson et al., 2008; Grant and Dawson, 1997; Hingson et al., 2006; McGue et al., 2001b) as well as other disinhibitory behaviors (Hingson et al., 2008;McGue et al., 2001b) and drug use. Results emerging from two large scale epidemiological studies representative of the U.S. population show a 1.3–1.6 times increased risk for AD in those who initiate alcohol use at 15 years of age or younger and a corresponding reduction in risk for alcohol dependence (by 14%) with each one-year delay in alcohol initiation (Dawson et al., 2008; Grant and Dawson, 1997). These findings were in keeping with findings from a Canadian sample, where the increased risk for AD in early-onset drinkers persisted even after controlling for exposure to childhood trauma and psychopathology (DeWit et al., 2000).
