In addition to providing a more reliable estimate of the heritability of AUD, such an analysis could address four additional important questions. First, several early twin and adoption studies suggested that there were quantitative sex effects in the genetic factors for AUD – that genetic effects were stronger in males than in females (Goodwin et al. 1973; Bohman et al. 1981; McGue et al. 1992). The studies that found differential genetic effects as a function of sex, however, often relied on small samples, especially of females. Most recent, larger studies have been unable to detect genetic differences between the sexes. Accordingly, a quantitative meta-analysis of a now larger body of studies would more accurately evaluate this hypothesis.
