Background: This study was designed to assess whether nonalcoholic offspring from families with a high density of alcohol-dependent individuals have altered hypothalamic-pituitary-adrenal (HPA) axis dynamics compared with nonalcoholic subjects without a family history of alcohol dependence.
Methods: Seventy-eight nonalcoholic subjects aged 18 to 25 were enrolled in the protocol. Thirty-nine subjects were offspring from families with a high density of alcohol dependence and were designated as family history-positive (FHP) subjects. Thirty-nine subjects were biological offspring of nonalcohol-dependent parents and were designated as family history-negative (FHN) subjects. Subjects received naloxone hydrochloride (0 and 125 microg/kg) and cosyntropin (0, 0.25 microg, and 250 microg) in double-blind, randomized order and cortisol was monitored. A subset of subjects (11 FHP, 11 FHN) was admitted to the General Clinical Research Center to measure serum cortisol levels every 30 min for 24 hr.
Results: FHP subjects had an increased cortisol response to opioid receptor blockade induced by naloxone. However, no group differences in cortisol were uncovered during administration of cosyntropin or during monitoring of the cortisol circadian profile.
Conclusion: These observations suggest that differences in the cortisol dynamics between FHP and FHN subjects are unmasked by opioid receptor blockade directed at the hypothalamus, but not when cortisol levels are directly provoked at the level of the adrenal gland. In addition, unprovoked cortisol secretion monitored over a 24-hr interval cannot distinguish FHP from FHN subjects.