Estimating genetic and environmental effects of alcohol use and dependence from a national survey: A ''quasi-adoption'' study''

Objective: A growing number of studies have examined the role of genetic and environmental influences on various aspects of alcohol use and abuse for women and men. We briefly review relevant twin and adoption studies; overall, these studies suggest: (1) both genetic and environmental factors play a role in the development of various alcohol-related problems, (2) these factors affect both males and females, and (3) genetic factors may be more significant For males than females. Method: This study is the first to address the question of genetic and environmental effects using data from a nationally representative probability sample, the National Health Interview Survey, 1988 Alcohol Supplement (NHIS-88A). We model the effects of biological family history of alcoholism (FHB) and environmental exposure to alcoholism during childhood (FHE) on (1) whether the respondent ever drank (current/former drinker), and, given that the respondent is a current drinker, (2) whether he or she developed DSM-III-R symptoms of alcohol dependence. Results: Results suggest (1) main effects of FHB and FHE on both current/former drinker and alcohol dependence and (2) evidence of greater FHB effects among males. No other gender differences were detected, and no gene by environment interaction effects were found, either for all respondents or by gender. Conclusions: Results are consistent with previous research showing a greater effect of genetic risk factors among men than women, yet important effects of both environment and generic factors for both sexes. The study design appears to provide an alternative to standard twin and adoption studies as a way to separate genetic and environmental risk factors, with both advantages and disadvantages compared to such designs. Some of these disadvantages might be addressed in questionnaire construction, but some are probably inherent.