Acquisition and reacquisition (relapse) of drug abuse: modulation by alternative reinforcers.

Most of the behavioral pharmacology research that has examined variables controlling drug self-reinforced behavior has been concerned with well-trained steady-state levels of drug-maintained responding. Little attention has been directed toward transition states such as the initial acquisition of drug-reinforced responding or reacquisition of responding after a period of abstinence (relapse). It is especially important to have animal models for these stages of the addiction process because ethical considerations do not allow these processes to be thoroughly studied in the human laboratory. The purpose of this chapter is to describe animal models for acquisition and reacquisition (relapse) of drug self-administration and to examine the effect of nondrug alternative reinforcers on these processes.