Alcohol dependence and excess drinking are leading causes of morbidity and premature death (Di Castelnuovo et al., 2006), affecting 5.4% of the general population lifetime (Kessler et al., 2005). The age at onset of alcohol dependence varies widely, with a consistent peak at age 18–19 years old and then a rapid decline of onset after 25 years old (Li et al., 2004; Reich et al., 1998). The age at onset is an important characteristic of alcohol dependence in most of the existing typologies. These typologies diverge in the number of types as well as in the clinical variables included in their models, co-morbid addictive disorders or antisocial personality disorder being sometimes excluded. Despite this high variability and the lack of scientific validation of the definition of a specific threshold, age at onset of alcohol dependence continues to be included in most of alcohol dependence typologies. Indeed, early onset of alcohol dependence is associated with a family history of alcohol use disorders (Limosin et al., 2001), and some genetic markers may particularly (Edenberg et al., 2008) or specifically (Dahmen et al.,
