There have been some modest differences across model results in different U.S. groups. All models to date have supported a direct link between a low LR to alcohol and heavier drinking and alcohol problems (e.g., Schuckit et al., 2004, 2008a, 2008c, 2009a, 2010), and all indicate that one or more of three additional characteristics statistically partially mediate the relationship between a low LR and adverse alcohol outcomes. Most support a significant contribution to mediation by using alcohol to cope with stress (COPE), and several have indicated that more positive expectations of the effects of alcohol (EXPECT) partially mediate how low LR relates to the drinking characteristics, but not all studies agree (Schuckit et al., 2008c, 2009a). There is similar variability regarding the possible mediational role for heavier substance using peers (PEER) (Schuckit et al, 2004, 2008a, 2008c, 2009a). The variation across studies regarding statistical partial mediators of the relationship of LR to heavy drinking and problems could reflect differences among samples, but it is also possible that some of the variability in performance of model components could be a consequence of the relatively modest sample sizes often available for these analyses.
