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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.addbeh.2005.09.005 Byline: Sarah H. Heil (a), Matthew W. Johnson (b), Stephen T. Higgins (c), Warren K. Bickel (d) Keywords: Delay discounting; Substance abuse; Cocaine; Abstinence; Discounting rates Abstract: Higher rates of delay discounting have been consistently noted in substance abusers compared to non-drug-using matched controls. Additional data from some studies comparing discounting rates in current versus former substance abusers suggest that discounting rates may be adaptable and that drug abstinence may be associated with reductions in discounting. The primary purpose of the present study was to determine whether a period of cocaine abstinence (at least 30 days) resulted in altered discounting rates of money in a population of primary cocaine-dependent patients compared to current cocaine users and non-drug-using matched controls. Results suggest that there was no difference in discounting between currently abstinent and currently using cocaine-dependent outpatients. When these two groups were combined, cocaine-dependent patients showed higher discounting rates than non-drug-using matched controls. These data replicate previous work in cocaine-dependent and other substance abusers compared to non-drug-using controls and suggest that a longer period of abstinence may be required to modify discounting in this population. Author Affiliation: (a) Department of Psychiatry, University of Vermont, United States (b) Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, United States (c) Departments of Psychiatry and Psychology, University of Vermont, United States (d) Department of Psychiatry, University of Arkansas, United States

Ninety-four smokers completed the delay discounting procedure for either hypothetical amounts of money, $10 (money) and $1000 (money) or hypothetical amounts of cigarettes ($10 and $1000 worth of cigarettes). We investigated how variables previously found to be related to rates of delay discounting accounted for the observed results. These variables included the following: demographic information, smoking characteristics, executive function abilities, impulsivity, time perception, and the Utility Measure of Cigarette Reinforcing Efficacy (UMCE). Education level and UMCE were each significantly correlated with 3 out of 4 of the discounting measures. Moreover, the largest effect sizes observed were between these two measures and the four discounting measures. All potential discounting predictors were also investigated using step-wise linear regression with Bayesian Information Criterion (BIC) analysis—these BIC models revealed that education level and UMCE accounted for large portions of the variance. We conclude that education level and UMCE were the most consistent predictors of discounting. This data is discussed within the framework of a widely accepted neuroeconomic model that suggests that two brain systems separately assess two separate facets of decision-making, and the interplay between these two systems determines self-control in smokers. We hypothesize that education level and UMCE may serve as surrogate measures of the functionality of these two systems and that discounting may be a sentinel measure of self-control., (Copyright © 2015 Elsevier Ltd. All rights reserved.)