There are several limitations of this research. The low density coverage of the 370K array may have contributed to negative findings. While the family-structured sampling design that we have used remains powerful for quantitative phenotypes, this is achieved at the cost of a loss of power for alcohol dependence diagnosis: in a general community sample the majority of such cases will be mild, and cases and their unaffected siblings may differ only modestly, in terms of symptom count. Second, while the study at the time it was implemented was powerful, considering anticipated effect sizes, subsequent findings across many complex phenotypes suggests that it is seriously underpowered given effect sizes that are likely to emerge for alcohol consumption and dependence outcomes. Third, our strategy of relying upon convergence of findings across consumption and dependence phenotypes (14) could cause us to miss associations that are specific to dependence. Finally, the cohorts that we have used in this research mostly were raised at a time of restrictive Australian divorce practices, so that even in families with parental alcoholism, it was usual for that
