The final stage involves at-risk drinkers who are progressing toward an AD diagnosis (see Table 3, Stage III). Risk factors accelerating progression to AD were ODD, CD, MDD, Phobia, and Traumatic life events. These findings that are often reported in the literatures on the epidemiology or the comorbidity of AD diagnosis (Merikangas et al., 2010; Sher et al., 2005; Zucker et al., 1995). The frequent comorbidity observed between psychiatric disorders and AD diagnosis has also been the subject of behavioral genetic examination. The consistent finding is that common genetic variation explains much of the observed comorbidity between psychiatric risk factors and AD (Kendler & Prescott, 2006; Krueger, Markon, Patrick, Benning, & Kramer, 2007; Slutske et al., 1998). Furthermore, according to Merikangas and McClair (2012), genetic epidemiological studies have consistently demonstrated that environmental factors play an important role in exposure to and initial use of substances, but that genetic factors have a major influence on progression of use to dependence. To the extent this is true, the expression of genetic risk would be more closely associated with the final stage of
