There was a small, albeit non-significant reduction in effect size in the association between familial alcoholism and obesity among women after adjusting for major depression the only non-substance related psychiatric diagnosis assessed in both surveys and this reduction may have been larger if other psychiatric disorders has been assessed in both surveys. Familial alcoholism may lead to obesity, in part, through psychiatric comorbidity. Other causal mechanisms, including common etiology for obesity and other psychiatric disorders that correlate with alcoholism risk are also plausible.39–41 Twin models suggest some overlap between the genetic etiology of depression and alcoholism; interestingly, evidence for this overlap is stronger for women than for men.42–44 Regardless of the role of depression other psychiatric disorders in the causal pathway between familial alcohol risk and obesity, documentation of this association, and its change over time, is a significant step in understanding obesity-associated characteristics in a subset of the population.
