We found that impulsivity uniquely predicted levels of hyperactive–inattentive symptoms, conduct problems and alcohol problems, as well as change in these symptoms over 18 months. On the other hand, we found that sensation seeking uniquely predicted only alcohol problems and change in these symptoms over 18 months. All of these effects survived correction for multiple testing. These findings are consistent with previous studies [34–40]. Results confirm the notion that impulsivity confers broad risk for multiple externalizing problems, possibly because general deficits in impulse control and inhibition result in the expression of a wide array of problematic behaviors [40]. Results also confirm the relative specificity of sensation seeking in predicting alcohol problems. This unique relation may be due to the fact that individuals with high sensation seeking have an increased drive for reward and stimulation, which they attempt to satisfy by using/misusing alcohol [40, 41]. It is this alcohol misuse that likely leads to the development of alcohol problems. Finally, although some studies found evidence for a unique, albeit weak, effect of sensation seeking on conduct problems [35, 36, 38, 39],
