Including both clinically relevant behaviors in combination with disinhibited personality traits in a common factor model of externalizing represents a broader approach than used previously in models of problem behavior (Donovan & Jessor, 1985; Donovan et al., 1988). This approach complements the previous finding that enrichment of associations with this gene set extends beyond clinical symptomology into individual differences in these personality traits (Aliev et al., 2015). That is, in addition to identifying enrichment in a series of separate analyses for alcohol and drug dependence symptoms, antisocial behavior symptoms, and conduct disorder symptoms, Aliev and colleagues reported the strongest enrichment effect for sensations seeking personality. We believe it is important to consider both behavior and personality traits when examining the externalizing spectrum, given the strong phenotypic associations between sensation-seeking/impulsive personality facets and manifestations of externalizing behavior (e.g., problematic alcohol use; Dick et al., 2010; Hittner & Swickert, 2006) and previous evidence from twin studies that much of the genetic influence on antisocial behavior is shared with disinhibited personality traits (Harden et al., 2012; Mann et al., under review). Of note,
