Understanding whether GABRA2 predicts these externalizing problems indirectly, through disinhibition, will inform the mechanisms that underlie these relations and provide a further test of whether GABRA2 does confer risk for broad externalizing symptomatology. In addition, examining these mediational links is important because a recent meta-analysis demonstrated that genetic effects were stronger on trait measures of impulsivity (e.g., Eysenck Personality Inventory) compared to manifestations of impulsivity in clinical symptoms of attention deficit/hyperactivity disorder [31]. Thus, genetic effects might be more clearly detected when using trait measures of behavioral disinhibition than measures of symptoms of disorder.
