The authors evaluated changes in serum prolactin levels as a measure of
differences in response to ethanol between 30 healthy, drinking, young
adult sons of alcoholics and 30 matched control subjects with no family
history of psychiatric or substance abuse problems. The control subjects
were matched for demographic variables, drug use histories, and alcohol use
histories. Each individual was tested on three occasions, receiving, in
random order, placebo, 0.75 ml/kg of ethanol, and 1.1 ml/kg of ethanol.
Controlling for baseline prolactin measures and hormonal changes after
placebo, the authors found that the sons of alcoholics had significantly
lower prolactin levels in response to the high-dose ethanol challenge.