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| Delay Discounting, Substance Abuse, and Gambling |
| Sunday, May 24, 2009 |
| 1:30 PM–2:50 PM |
| North 226 C |
| Area: BPH/EAB; Domain: Experimental Analysis |
| Chair: Kathryn A. Saulsgiver (University of Vermont) |
| Abstract: Delay discounting (DD), or the degree to which a future reward is discounted, has been shown to predict treatment outcome in substance abusers (Yoon et al., 2007). Higher rates of DD have also been found in pathological gamblers in comparison to matched controls (e.g., Alessi & Petry, 2003). This symposium examines how discounting rates are associated with treatment outcome in various substance abusing populations. This symposium also bridges the gap between human and non-human research by examining the effects of pre-session pramipexole in a DD paradigm and on an animal model of gambling. |
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| Delay discounting and other variables associated with pregnant smokers: Those who quit vs. those who don't |
| JIN HO YOON (Baylor College of Medicine), Stephen T. Higgins (University of Vermont) |
| Abstract: Maternal smoking is a leading preventable cause of poor pregnancy outcomes and infant morbidity and mortality. Despite the existence of effective interventions, end-of-pregnancy rates are often low (<20%). Greater knowledge of factors influencing smoking cessation during pregnancy is therefore needed to understand continued smoking in this population and to aid in the development of more effective interventions. Participants (N = 131) were involved in two separate clinical trials examining the influence of incentives for either promoting or maintaining smoking abstinence during pregnancy and up to 6-months postpartum. One group of women was still smoking at intake, whereas the other group had quit smoking prior to intake once they discovered that they were pregnant. Our group was therefore in a unique position to identify potential variables associated with women who were more or less likely to quit smoking once they discovered that they were pregnant. Socio-demographic, smoking characteristics, and history of depressive symptoms were assessed during at study intake. Additionally, impulsivity was assessed using a delay-discounting task for hypothetical monetary rewards. Delay discounting was found to be significantly different between the two groups in univariate analyses and the general pattern of results showed that women who were still smoking and those that had stopped were differentiated by variables traditionally associated with smoking availability and severity. |
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| Baseline delay discounting predicts response to a behavioral smoking intervention among opiate maintained patients |
| KATHRYN A. SAULSGIVER (University of Vermont), Kelly Dunn (University of Vermont), Stacey C. Sigmon (University of Vermont), Matthew P. Bradstreet (University of Vermont), Ed Reimann (University of Vermont), Sarah Heil (University of Vermont), Stephen T. Higgins (University of Vermont) |
| Abstract: Delay discounting (DD) has been used to characterize potentially important differences in dealing with reinforcement delay between individuals with and without substance use disorders and, more recently, to predict treatment response (Dallery & Raiff, 2007; Doran et al., 2004; Krishnan-Sarin et al., 2007; Yoon et al., 2007). DD was examined as part of a larger evaluation of a contingency-management intervention for reducing cigarette smoking among methadone- and buprenorphine-maintained patients (Dunn et al., in press). In this 2-week study, 15 participants received voucher-based reinforcement contingent upon smoking abstinence. DD was assessed on various Study Days using hypothetical monetary rewards over a range of delays. We examined the data using both the conventional k-value calculation (Mazur, 1987) and a more recently-developed ED50 calculation (Yoon & Higgins, 2008). To examine the relationship between baseline DD and subsequent smoking abstinence, participants were dichotomized into low (Lo-DD, n=7) and high (Hi-DD, n=8) groups based on baseline ED50. Preliminary analyses show that Lo-DD participants achieved more smoking abstinence, as evidenced by more smoking-negative samples (85.7% vs. 51.8%; p< .001) and longer durations of continuous abstinence (10.6 vs. 5.6 days; p=.11) than Hi-DD, respectively. Participants were also dichotomized based on whether they abstained (n=10) or continued to smoke (n=5) during the study. Abstainers had significantly lower baseline k-values (.0007 vs. .009; p=.02) and marginally higher ED50 values (3.75 vs. 0.31 years; p=.12) than Smokers, respectively. These preliminary data suggest that baseline DD may predict subsequent response to a smoking intervention and extend these findings to opioid-maintained smokers. |
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| Delay Discounting in Cocaine Dependent Outpatients |
| YUKIKO WASHIO (University of Vermont), Matthew P Bradstreet (University of Vermont), Gary J. Badger (University of Vermont), Sarah Heil (University of Vermont), Stephen T. Higgins (University of Vermont) |
| Abstract: The observation that the value of a reinforcer decreases as a function of increased delay to delivery is described as delay discounting (DD) (Bickel & Marsch, 2001; Reynolds, 2006). Substance abuse can be described as a real-world example of DD, in which the immediate reinforcing effects of a drug is preferred over the longer-term benefits of abstaining from drug abuse (Yoon & Higgins, 2008). The literature reliably demonstrates that drug abusers exhibit greater DD compared to non-drug abusers (Yoon et al., 2007). DD of monetary values was examined among cocaine dependent outpatients as part of our ongoing randomized clinical trials with community reinforcement approach plus vouchers. Compared within subjects, there was no visually detectable change in k values, a measure of the rate of discounting, between the time of intake and that of 6-weeks into the recommended 24-weeks of treatment. These results support a position that DD of monetary reinforcement among these cocaine-dependent outpatients appears to be a relatively stable behavioral characteristic. This study is still ongoing, and additional patients and analyses will be added to the current data set. |
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| Delay Discounting Processes in Pathological Gambling: Pharmacological Induction of Impulsive Behavior in the Nonhuman Laboratory |
| PATRICK S. JOHNSON (University of Kansas), Adam T. Brewer (University of Kansas), Jonathan W. Pinkston (University of Kansas), Jeff S. Stein (University of Kansas), Monica T. Francisco (University of Kansas), Gregory J. Madden (University of Kansas) |
| Abstract: Mazur’s (1987) hyperbolic discounting equation has been suggested to describe not only the discounting of delayed rewards but also the discounting of rewards requiring significant effort (e.g., Grossbard & Mazur, 1986). In this way, severe forms of impulsive behavior such as pathological gambling may be directly correlated with rates of delay discounting (Madden, Ewan, & Lagorio, 2007). In fact, studies investigating delay discounting in pathological gamblers oftentimes reveal higher rates of discounting for gamblers than for matched controls (e.g., Alessi & Petry, 2003).
Findings from experimental work with nonhuman subjects in these areas (i.e., delay discounting, pathological gambling) will be discussed. Clinical reports have implicated pramipexole, a D2/D3 dopamine receptor agonist commonly prescribed for Parkinson’s disease, in the development of a number of impulse control disorders (e.g., Dodd, Klos, Bower, Geda, Josephs, & Ahlskog, 2005). The effects of pre-session pramipexole were studied in a delay discounting paradigm and in an animal model of gambling. Pramipexole significantly increased impulsive choice above saline levels in the delay discounting task; the drug also significantly increased preference for gambling-like sources of reinforcement in the gambling model. Results of these studies will be interpreted with respect to the purported linkage between delay and effort discounting. |
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