Stress and conflict conditions leading to and maintaining voluntary alcohol consumption in rats.

Four experiments were conducted to investigate the effects of unavoidable shock, conflict conditions, taste, and food deprivation on the voluntary consumption of alcohol by rats. Experiment 1 showed that when rats were given unavoidable shocks for one hour every day, those living in their home cages consumed greater amounts of a 5% ethanol solution than did rats living in the shock chambers. Experiment 2 revealed that this increased alcohol consumption was maintained and further elevated when these same rats were subjected to conflict, and it did not decrease when the conflict conditions were terminated. When the unavoidable shock conditions were repeated in Experiment 3 with naive rats and the fluid choice consisted of a plain sucrose solution and one containing alcohol, rats in both the shock box and safety cage living conditions consumed very little of the sucrose-plus-alcohol solution. Rats living in the aversive environment even decreased consumption of the plain sucrose solution. Experiment 4 showed that simple food deprivation can also result in an increased intake of an alcohol solution. The tension reduction hypothesis cannot account for these results: they demonstrate that deprivation can influence alcohol consumption, and indicate that an aversive environment can interfere with drinking of any solution. The results also demonstrate both the positive and negative properties that alcohol can have.