The Contribution of Pavlovian Conditioning to Drug Tolerance and Dependence

Summary A progressively smaller response to a drug over repeated administrations defines tolerance. While traditional views of tolerance have assumed that the physiological changes underlying tolerance result simply from past exposure to the drug per se, it has become increasingly apparent that environmental cues present at the time of drug administration contribute to tolerance. The contribution of such drug‐predictive environmental cues has been incorporated in a Pavlovian conditioning model of tolerance. The present paper summarizes data supporting the conditioning analysis of tolerance. The relevance of this analysis for the management of tolerance in clinical settings, and for drug withdrawal symptoms, is discussed.