In each of the two-factor models (EXT-ARF and BD-SUB), the factors were similarly genetically correlated with external criteria such that the correlations of effect sizes were ≥0.95 and statistically significant differences were, for the most part, small in magnitude. Nevertheless, there were potentially meaningful differences in the associations of externalizing and SUDs with substance use outcomes and other forms of psychopathology. For example, addiction risk was significantly more strongly associated with cigarettes per day, major depressive disorder and schizophrenia. The expanded externalizing factor in the common factor model was strongly genetically correlated with a variety of relevant psychological, substance use and personality traits.
