for each alcohol use phenotype occurred at the later ages included in the sample, so it is possible that the effect may continue to increase with age, beyond the ages at which our participants were assessed. Alternatively, though, rather than continuing to increase with age, the magnitude of the effect of ALDH2 polymorphism may peak when alcohol use is typically highest - that is, during young adulthood (Sher et al., 2005). In fact, in this sample, the effect of ALDH2*2 possession appears to level off or even diminish near the eldest observations. Although previous studies have noted increasing effect of ALDH2 polymorphism across periods of one or more years during young adulthood (Doran, et al., 2007; Kim et al., 2010), the development of the effect of ALDH2*2 possession upon alcohol use between young adulthood and later adulthood has yet to be studied.
