Neuronal and Psychological Underpinnings of Pathological Gambling

Abstract

Although pathological gambling (PG) is a prevalent disease, its neurobiological and psychological underpinnings are not well characterized. As legal gambling increases in prominence in a growing number of casinos as well as on the internet, the potential for a rise in PG diagnoses warrants investigation of the disorder. The recent reclassification of PG as a behavioral addiction in the DSM-5 raises the possibility that similar cognitive and motivational phenotypes may underlie both gambling and substance use disorders. Indeed, in this Research Topic, Zack et al. (2014) tested the hypothesis that exposure to reward unpredictability can recruit brain dopamine (DA) systems in a similar way to chronic exposure to drugs of abuse (see also Singer et al., 2012). Over the years a variety of models have proposed that alterations in DA signaling may mediate the transition from drug use to dependence; similarly, the hypothesis that aberrant DA responses may influence the transition from recreational, to problematic, and finally PG has only recently begun to be tested. The collection of articles in this Research Topic highlights the complexity of PG and posits several theories of how dopaminergic signaling may contribute to behavioral maladaptations that contribute to PG.In this Research Topic, Paglieri et al. (2014) report a growing incidence of PG with a lack of effective treatments. As described by Goudriaan et al. (2014) (this Research Topic), PG is thought to result from "diminished cognitive control over the urge to engage in addictive behaviors" that manifests in the inability to control desire to gamble despite negative consequences. PG is characterized by several cognitive dysfunctions, including increased impulsivity and cognitive interference. Similar to drug addictions, gambling behavior is powerfully modulated by exposure to gambling-related conditioned stimuli. In this Research Topic both Anselme and Robinson (2013) as well as Linnet (2014) describe the supporting role of gambling-related cues in this behavioral addiction. Anselme and Robinson (2013) present a series of findings suggesting that surprising non-rewards enhance incentive salience attribution to conditioned cues in conditioning procedures as well as during gambling episodes. They discuss a possible evolutionary origin of this counterintuitive process. Linnet (2014) reviews the contribution of DA signaling to incentive salience and reward prediction. Noting the research demonstrating brain activation during gambling tasks despite the possibility of a loss, he suggests a role for DA dysfunction in reward "wanting" and anticipation.Ventral striatal activation is thought to be critical for the attribution of incentive salience to reward-related cues. In this Research Topic, Lawrence and Brooks (2014) found that healthy individuals who are more likely to display disinhibitory personality traits, such as financial extravagance and irresponsibility, show increased capacity for ventral striatal DA synthesis. Thus it is possible that individual variation i...