The HR subjects in general showed increased impulsivity on all subscales and total score of the BIS compared to the LR group, although subgroup-specific findings (i.e., age group and gender related) were also present (Fig 6). Studies have reported higher impulsivity scores and increased prevalence of externalizing disorders in general, and in particular substance use disorders [195–198]. It is also interesting to observe that while younger subjects of both genders showed significant differences between risk groups on all subscales of the BIS, older females displayed significant differences in nonplanning and motor impulsivity, while the older males were significantly different only for motor impulsivity. Similar to our findings, age and gender differences in impulsivity have been reported in the literature [199,200]. It has also been reported that the association between gender and risk for alcohol problems may be mediated by impulsivity [200]. Further, etiological connections between impulsivity and alcoholism and/or other SUDs have also been proposed (for reviews, see [201–203]). Consistent with this view, the current study has also found that the prevalence rate of externalizing disorders was significantly higher in
