A number of differences in sample and study design between the present study and that of Schuckit et al. (2012) may explain our failure to fully replicate their results. The two samples had very different compositions in terms of ethnicity and gender, which may have been correlated with differences in both genetic factors contributing to the LR to alcohol, and social and environmental factors influencing alcohol use and response to the programs. Because Schuckit and colleagues’ study required participants to complete all modules, that may have contributed to the prevention programs having a stronger effect. Therefore it may be that maximizing participant involvement or adding booster modules to reinforce the prevention principles could increase the effectiveness of tailored programs. In addition, their sample was of second-semester freshmen and excluded anyone with no drinking over the previous six months, so the overall levels of alcohol use were higher in their sample, particularly for the high LR group. However, we note that we did not find differences in the results when using data only from heavy baseline drinkers (results not shown).
