Our estimates of the heritability of alcohol consumption in early adolescents are comparable with that of a previous study of adolescent alcohol use (Rhee et al. 2003) and another of adolescent alcohol problems (Rose et al. 2004). However, they are considerably lower than other reports, which range from 0.25 to 0.67 for a variety of alcohol-related phenotypes (Edwards et al. 2011a, b; Geels et al. 2012). Our use of retrospective reports could contribute to discrepancies, though genuine population and cohort differences probably also contribute. Generally, the heritability of alcohol use increases from adolescence into adulthood (Bergen et al. 2007), consistent with the estimates reported here. This increase in heritability is typically accompanied by corresponding decreases in shared environmental influences (Edwards et al. 2011a, b; Geels et al. 2012).
