A Behavioral Economic Analysis of the Reinforcing Effects of Drugs: Transition States of Addiction
Marilyn E. Carroll Una C. Campbell University of Minnesota
Behavioral economic analyses have been applied to drug-reinforced behavior, and these methods have identified the optimal economic conditions under which prevention or treatment of drug abuse should occur (e.g., see reviews by Bickel & DeGrandpre, 1995, 1996; Bickel, DeGrandpre, & Higgins , 1993, 1995; Carroll, 1996; Hursh, 1991; Vuchinich & Tucker, 1988). Most of these studies involve paradigms in which there are ongoing, steady- state rates of drug self-administration in drug-experienced animals or humans. The purpose of this chapter is to consider using a behavioral economic framework to study the transition phases of the addiction process, such as acquisition in the naive animal and reinstatement of drug-seeking behavior (i.e., relapse) during a period of abstinence. Two economic concepts that are applied to studies of acquisition and reinstatement are unit price and substitution. In addition to these topics, a number of new findings are discussed that have emerged since acquisition and reinstatement were last reviewed ( Carroll, 1996; Carroll & Comer, 1996; de Wit, 1996; Ramsey, 1991).
The initial acquisition of drug-reinforced behavior has been described as a transition state. At this phase of the drug addiction process, there is a shift from little or no drug-maintained responding to high rates of drug-seeking behavior. Because it is unethical to study the acquisition process in drug-