Drug and Alcohol Dependence 76 (2004) 107–111 Short communication Long-term heavy marijuana users make costly decisions on a gambling task Christopher T. Whitlow a , Anthony Liguori a , L. Brooke Livengood a , Stephanie L. Hart a , Becky J. Mussat-Whitlow b , Corey M. Lamborn a , Paul J. Laurienti c , Linda J. Porrino a,∗ a Department of Physiology and Pharmacology, Center for the Neurobiological Investigation of Drug Abuse, Wake Forest University School of Medicine, Medical Center Boulevard, Winston Salem, NC 27157-1083, USA b Department of Educational Research Methodology, University of North Carolina at Greensboro, Greensboro, NC 27402-6170, USA c Department of Radiology, Wake Forest University School of Medicine, Winston Salem, NC 27157-1083, USA Received 9 December 2003; received in revised form 25 March 2004; accepted 20 April 2004 Abstract Rationale: Chronic marijuana use has been associated with impairments of learning, memory, and executive functions. Little is known, however, about the effects of marijuana use on other cognitive domains, such as decision-making, which are thought to play an important role in addiction and drug abuse. Objectives: The purpose of the present study was to determine if long-term heavy marijuana users employ different decision-making strategies than individuals with minimal marijuana exposure. Methods: Volunteers were assigned to a cannabis (n = 10) or control group (n = 10) based upon history of prior marijuana use. Demographic and neuropsychological variables were evaluated, and a decision-making task—the gambling task (GT) was administered. Results: Although few demographic and neuropsychological differences were noted between groups, marijuana users made more decisions that led to larger immediate gains despite more costly losses than controls. Conclusions: These data suggest thatlong-term heavy marijuana users may have specific deficits in the ability to balance rewards and punishments that may contribute to continued drug-taking behavior. It is unknown, however, whether the basis for such deficits might be attributed directly to marijuana exposure or pre-existing genetic or behavioral differences. © 2004 Elsevier Ireland Ltd. All rights reserved. Keywords: Cannabis; Marijuana; Neuropsychological effects; Decision-making; Gambling task 1. Introduction A recentstudy in animal models reported that chronic 9 -tetrahydrocannibinol (THC),the active ingredient in marijuana, produces persistent alterations of functional ac- tivity in portions of the prefrontal cortex, homologous to the human orbitofrontal cortex, and amygdala (Whitlow et al., 2003).Although deficits on the performance of memory, attention and executive function tasks, generally associated with the dorsolateral prefrontal cortex and the hippocam- pus, have been reported in heavy marijuana users ( Pope and Yurgelun-Todd, 1996; Fletcher et al., 1996; Heishman et al., 1997; Solowij, 1998; Solowij et al., 2002), few studies have explored the effects of marijuana use on tasks associated with the amygdala and orbitofrontal cortex. ∗ Corresponding author. Tel.: +1 336 716 8575; fax: +1 336 716 8501. E-mailaddress: lporrino@wfubmc.edu (L.J. Porrino). The Iowa gambling task (GT) was designed to examine decision-making deficits exhibited by people with damage specifically to ventral and medial prefrontal cortex ( Bechara etal.,1994).In this task, subjects choose cards from four decks,with each choice resulting in monetary wins along with occasional monetary losses. Advantageous decks have small wins, but smaller losses, resulting in an overall gain. Disadvantageous decks have larger wins, butlarger penal- ties,resulting in an overall loss.This task therefore, is thought to simulate real-life decision-making involving un- certainty, rewards, and punishments. Patients with damage to prefrontal cortex and amygdala, as wellas abusers of alcohol, cocaine, heroin, and methamphetamine, all show impairments on the performance of the gambling task ( Petry et al., 1998;Bechara etal., 1999;Mazaset al., 2000; Bartzokis et al.,2000;Grantetal.,2000;Bechara et al., 2001;Bechara and Damasio, 2002).Given thatchronic THC exposure is associated with persistent decrements in functional activity in medial prefrontal cortex and amygdala 0376-8716/$ – see front matter © 2004 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.drugalcdep.2004.04.009