Behavioral and neuroeconomics of drug addiction: competing neural systems and temporal discounting processes

Abstract

We review behavioral- and neuroeconomic research that identifies temporal discounting as an important component in the development and maintenance of drug addiction. First, we review behavioral economic research that explains and documents the contribution of temporal discounting to addiction. This is followed with recent insights from neuroeconomics that may provide an explanation of why drug-dependent individuals discount the future. Specifically, neuroeconomics has identified two competing neural systems that are related to temporal discounting using brain-imaging techniques that examine the relative activation of different brain regions for temporal discounting. According to the competing neural systems account, choices for delayed outcomes are related to the prefrontal cortex (i.e., the "executive system") and choices for immediate outcomes are related to the limbic brain regions (i.e., the "impulsive system"). Temporal discounting provides a useful framework for future imaging research, and suggests a novel approach to designing effective drug dependence prevention and treatment programs.

Figures

Figure 1

Median indifference points between large delayed and small immediate heroin and monetary rewards. Opioid-dependent and control participants’ monetary choice data are shown at the top, whereas the bottom shows opioid-dependent participants’ monetary and heroin choice data. Reprinted from Madden et al., 1997.