Two multivariate approaches were used to determine whether the same genetic factors contribute to the phenotypic correlation between AUD symptoms: (1) The Common Pathway Model (CPM) and (2) Exploratory Genetic Factor Analysis (EGFA). In addition, the EGFA was followed up with three confirmatory factor analyses to determine the most parsimonious genetic architecture across the criteria. Three multivariate models were tested: (a) a common genetic factor model, (b) a 2- factor model where factor-1 was indicated by the three former DSM-IV abuse symptoms and craving and factor-2 was indicated by the seven former DSM-IV dependence items), and (c) a 2-genetic factor model in which craving was allowed to cross-load across the factors). The CFA models were compared using the Akaike Information Criteria (AIC) (Akaike, 1973).
