In summary, the human low LR hormone differences reported are rather small, and the low LR and normal response (or FHP and FHN) populations overlap substantially. The animal data are relatively sparse, although there are clearly genetic differences in hormone responses to alcohol and innate differences in hormone and opioid receptor levels between genetically selected rat lines and among inbred mouse strains that could be examined in more detail. Overall, this is an area where we would be close to mechanisms, as rodent and human stress axes appear to work rather similarly. The available data, however, are not terribly encouraging, as the rodent data don’t point strongly toward genetic co-regulation of hormone responses to alcohol challenge and either drinking or withdrawal severity.
