Drinking to Dependence Risk Factors in Nonhuman Primates

Nonhuman primates (NHPs), in particular old-world monkeys, are excellent human surrogates for understanding putative risk factors, including genetic and epigenetic factors, behavioral traits, and stress and hormonal interactions. NHPs have been very informative in alcohol research because they will repeatedly drink intoxicating doses of ethanol, including drinking until signs of physical dependence upon alcohol appear. Perhaps even more informative is that NHPs show a wide distribution in the daily intake of alcohol (with resultant blood ethanol concentrations) when they have nearly constant access to alcohol (22. hrs/day). Given the individual differences in drinking alcohol repeatedly to intoxication, this chapter will address several main risk factors for developing alcohol dependence that have been documented in humans and can be studied in monkeys. These main factors include genetic mechanisms, stress and the HPA axis, age of onset of drinking alcohol, and temperament.