The findings of the current study also showed that motor and non-planning impulsivity components were the topmost features contributing to the classification of AUD individuals from controls. This finding reinforces the long-held notion that AUD and other externalizing traits are part of the externalizing spectrum disorders [105,106,107,108,109]. It is also known that AUD is associated with making impulsive choices during decision-making [16]. It is possible that the increased impulsivity manifested by AUD individuals may be due to altered FC across the frontal nodes [63] and/or relatively lower brain volumes of the frontal regions, as reported in our previous study [54]. Evidence from the imaging literature strongly suggest that both structural and functional aspects of the frontal lobes contribute to increased impulsivity in AUD patients [110,111,112,113]. Furthermore, recent studies have also reported associations between impulsivity and resting state measures of EEG power [114], EEG-based FC [115], and fMRI-based FC [36], suggesting that specific brain networks may mediate aspects of impulsivity in AUD, as well as other externalizing disorders. Therefore, identifying and quantifying behavioral impulsivity may contribute to improving prevention and intervention
