Of note, tobacco and marijuana use onset did not predict later alcohol problems. Moreover, significant interactions between the onset of regular drinking and drug use onset were not observed. However, this study focused only on alcohol outcomes. Future research should examine drug outcomes to explore whether this specificity applies to other drugs over time. For example, early marijuana use onset may be linked to later marijuana abuse, but not to later alcohol abuse. It would be important for future studies to examine gender and racial/ethnic differences as well. The present study was unable to appropriately address these differences due to the relatively small size of the sample. In addition, since the overarching study was designed to follow offspring of alcohol and drug-dependent fathers over time, the sample was a high-risk sample (ascertained through the community). As such, generalizability of the results should be made with caution. Because the study was not based on a clinical sample, an estimate of a clinical effect was not provided. Nevertheless, the findings have important clinical implications since they strongly suggest that individuals who postpone
