1. Opioid antagonists block alcohol self-administration in rats.
2. Opioid antagonists block the increase in alcohol intake following alcohol deprivation in humans
3. Opioid antagonists block the cue induced increase in alcohol intake in rats.
4. The opioid antagonist naltrexone reduces alcohol intake in alcohol dependent humans
5. Individuals with a family history of alcohol dependence have an increased B-endorphin response to alcohol.
6. A genetic variant of the Mu opioid receptor that has an increased affinity for beta endorphin is associated with increased alcohol induced dopamine release in the ventral striatum of humans and mice and monkeys with this variant have an increased preference for alcohol.
Individuals with a Family History of Alcoholism Have increased Pituitary ß-Endorphin Response to Alcohol

20 high risk white subjects (50% female, 20 – 30 years of age) with minimum of 2 generations history of alcoholism who drank an average of 7.6 days/month and 20 low risk white subjects (50% female) with no family history of alcoholism who drank an average of 7.4 days/month, drank placebo and 3 doses of alcohol (above) on 4 separate days. Peak blood alcohol was about .03, .08 and .12 gm/100 mL for the 3 doses. Alcohol did not change plasma cortisol levels in either group. (Constructed from data in Gianoulakis, C. et al. Arch Gen Psychiatry, 53: 250, 1966) ©2008 NBEP