As previously discussed by Prescott & Kendler (1999), two prevailing hypotheses have dominated our understanding of this relationship: the non-causal/common vulnerability (genetic and environmental) and the causal/environmental hypotheses. Our study sought to examine a third possibility – one that explores whether the genetic (and environmental) architecture of AD is different in those who begin their drinking careers early in life – this may be referred to as the Moderation/Interaction hypothesis.
