Effects of Pavlovian conditioning on the ethanol withdrawal syndrome in rats.

Male, hooded rats were made physically dependent upon ethanol using intravenous infusions. Following this induction procedure, physical dependence was maintained, but now a tone (CS) was associated with ethanol infusions (US) that reduced withdrawal distress. A pretest-posttest, counterbalanced, repeated measures design was used to assess the effects of three treatments (ethanol, tone, none) on withdrawal reactions (withdrawal signs, body temperature, open-field activity) measured under blind conditions. Only the ethanol treatment reduced withdrawal distress, suggesting that classical conditioning did not occur. The results are discussed in terms of recent conditioning theories of drug responses, and the potential role of stress in these reactions.