Anticipation of Pharmacological and Nonpharmacological Events: Classical Conditioning and Addictive Behavior

Typically, pharmacological phenomena such as tolerance, sensitization, and dependence have been viewed as resulting from the operation of feedback mechanisms: pharmacologically disturbed homeostatic functioning is countered by compensatory responses that restore physiological equilibrium. We summarize the results of research indicating that feedforward mechanisms (i.e., regulatory responses made in anticipation of a drug) also importantly …