As with all studies, it is important to recognize the limitations of the current work. First, most participants in the Youth Panel came from families recruited because of multiple family members with AUDs, and the generalizability to other samples needs to be determined. However, at least regarding the LR measure, the current SEM results are generally similar to analyses reported from the San Diego Prospective Study (SDPS) as well as the Avon Longitudinal Study of Parents and Children (ALSPAC) (Schuckit and Smith, 2006; Schuckit et al., 2011). Second, SEM analyses evaluate the potential validity of a specific hypothesized model, but do not demonstrate if that model is superior to other models. Third, the analyses were based on evaluating mediation by three Time 2 characteristics often used in our work (i.e., PEER, EXPECT, and COPE), and further study is required to evaluate additional possible mediators as well as moderators. Fourth, for reasons described in the Methods, only one externalizing measure, the Barratt, was available for use in these analyses, and it is important to evaluate additional impulsivity measures and other externalizing
