The findings from our study should be considered in the context of several limitations. First, the present study included offspring of either clinically ascertained families or unascertained comparison families. Thus, the offspring of the unascertained comparison families may not necessarily have the same risk factors as offspring from the clinically ascertained families (although we note that comparison families were not excluded on the basis of a history of substance use disorders). Second, because the COGA Prospective Study employs a rolling enrollment strategy and we limited our sample to participants between 21–25 years of age, some participants were only eligible for one assessment while still in our specified age range. Of note, the model that we employed can incorporate different numbers of assessments and periods between assessments across participants so that we were able to maximize the sample size from the available data. Third, we did not have any data on the characteristics of our participants’ partners, which would likely influence the drinking frequency of the participants, nor did we have information regarding the relationship length (particularly for those who were living as married), to consider the potential moderating effects of these factors.
