The effects of alcohol problems and smoking on delay discounting in individuals with gambling problems.

Problem gambling is an addictive behavior with high comorbidity with alcohol problems and smoking. A common feature shared by these conditions is impulsivity. Past research shows that individuals with any of these addictions discount delayed money at higher rates than those without, and that the presence of gambling and substance use lead to additive effects on discounting. To date, however, no study examined the impact of smoking on these associations. The goals of this study were to compare the discounting rates of gamblers with and without histories of alcohol problems and smoking, and assess the associations these addictions might have on discounting. We analyzed the discounting rates of treatment-seeking gamblers categorized into four groups based on their histories of alcohol and smoking. Results revealed effects of history of alcohol problems, and an interaction between smoking and alcohol problems, on discounting. Never smokers with histories of alcohol problems discounted money less steeply than the other groups of gamblers. These results suggest that smoking does not produce additional increases on discounting rates in individuals with other addiction problems and the small subpopulation of gamblers with alcohol problems who never smoked is less impulsive and may have unique risk and/or protective behaviors.