large body of evidence implicating negative emotionality as a risk factor for internalizing and externalizing disorders (e.g. Khan et al. 2005; Tackett et al. 2013), we expected that it would explain a significant proportion of the covariation among MDD and AUD. Finally, mounting evidence suggests that behavioral control is involved in risk for internalizing and externalizing psychopathology (e.g. Field et al. 2010; Kanske & Kotz, 2012), and we hypothesized that it would explain some degree of covariance, beyond what is accounted for by negative emotionality. The degree to which these factors account for covariation among these conceptually distinct disorders will help determine the extent to which they may be important targets for broad intervention efforts.
