As with paternal status, maternal maximum consumption effects were not secondary to a primary effect of alcohol dependence. In fact, associations with substance-related outcomes in particular were unaffected by adjustment for effects of alcohol dependence; adjusted and unadjusted effects were virtually identical. By contrast, associations between maternal alcohol dependence and substance-related phenotypes were entirely mediated by maximum consumption; partial (adjusted) regression coefficients tended toward zero. Although a diagnosis of alcohol dependence may reflect functional impairment, these results indicate that the maximum number of drinks consumed may more closely reflect the underlying vulnerability for substance-related problems.
