Delay Discounting in Drug Dependence

描述（由申请人提供）：越来越多地研究药物依赖者中延迟释放的折扣。该研究的结果是一致的，反映了药物依赖的一个重要方面。具体来说，这些研究表明，药物依赖者比匹配的对照组更容易贴现。此外，药物依赖参与者对药物依赖的贴现率高于对金钱的贴现率。前依赖或最近戒断的药物使用者的贴现率介于当前药物依赖个体和匹配对照之间，或者接近匹配对照的贴现率。此外，加强禁欲已被证明可以减少药物依赖者对金钱和香烟的折扣。总的来说，这些研究表明，药物依赖者比对照组折扣更多，药物依赖者中的过度折扣可能是药物使用的可逆效应。在这一竞争性的延续中，我们建议通过解决三个具体目标来继续这一富有成效的研究。第一个具体的目的是检查是否药物依赖的个人与合并症折扣延迟的药物比个人没有合并症。Exp. 1将通过比较阿片类药物依赖性吸烟者、阿片类药物依赖性非吸烟者、非阿片类药物依赖性吸烟者和非阿片类药物依赖性、非吸烟匹配对照的折扣来检查共病物质依赖性障碍。实验2将探讨吸烟者中的一种非物质依赖共病精神障碍，即抑郁症。具体来说，我们将比较抑郁的吸烟者，非抑郁的吸烟者，抑郁的非吸烟者和非抑郁的非吸烟匹配对照组的折扣。第二个具体目标是广泛比较吸烟者和非吸烟者的延迟和概率折扣。先前的一项研究报告说，吸烟者与不吸烟者在概率折扣方面没有区别。 先前的报告只考察了一个数量级的货币贴现。实验3将通过检查和比较延迟和概率折扣来系统地复制和扩展之前的研究。具体来说，我们将比较这两种类型的折扣与几种商品，每一个在几个幅度，在吸烟者和匹配的控制。第三个具体目标是检验折扣和节欲之间的关系。以前我们已经证明，戒烟者的折扣与不吸烟者的折扣没有区别。解释该观察结果的两个假设是：（a）成功戒烟的吸烟者在开始戒烟之前折扣较小（折扣较小导致戒烟）和（B）戒烟导致折扣较小。这些假设可能并不相互排斥。在实验4中，我们将研究是否有接近计划戒烟的个人折扣不同于目前吸烟者没有接近计划戒烟和前吸烟者。在实验5中，我们将继续我们最初的观察，加强禁欲对折扣的影响。具体而言，我们建议通过实施和取消应急管理程序，将这种观察结果复制和扩展到吸烟者。如果我们先前的工作被复制，那么当戒烟被加强时，折扣应该会减少。我们将通过确定当吸烟者复吸时折扣的减少是否会逆转来扩展这项工作。

DESCRIPTION (provided by applicant): The discounting of delayed reinforcers among the drug dependent has been increasingly studied. The results of that research are consistent and reflect an important dimension of drug dependence. Specifically, these studies have shown that drug-dependent individuals discount money more than matched controls. Moreover, drug-dependent participants discount their drug of dependence more than they discount money. Ex-dependent or recently abstinent drug users discount money either at a rate intermediate between current drug-dependent individuals and matched controls, or at a rate that approximates discounting of the matched controls. Furthermore, reinforcing abstinence has been shown to decrease the discounting of money and cigarettes in the drug dependent. Overall, these studies suggest that drug-dependent individuals discount more than controls and the excessive discounting among the drug dependent may be a reversible effect of drug use. In this competing continuation, we propose to continue this productive research by addressing three specific aims. The first specific aim is to examine whether drug-dependent individuals with co-morbidity discount delayed reinforcers more than individuals without that co-morbidity. Exp. 1 will examine co-morbid substance dependence disorder by comparing the discounting of opioid-dependent cigarette smokers, opioid-dependent non-smokers, non-opioid-dependent smokers, and non-opioid- dependent, non-smoking matched controls. Exp.2 will examine a non-substance dependence co-morbid psychiatric disorder among cigarette smokers, namely, depression. Specifically, we will compare the discounting of depressed smokers, non-depressed smokers, depressed non-smokers, and non-depressed, non-smoking matched controls. The second specific aim is to extensively compare delay and probability discounting in smokers and non-smokers. A prior study reported that smokers did not differ from non-smokers on probability discounting. That prior report examined the discounting of money at only one magnitude. Exp.3 will systematically replicate and extend that prior study by examining and comparing delay and probability discounting. Specifically, we will compare those two types of discounting with several commodities, each at several magnitudes, in both smokers and matched controls. The third specific aim is to examine the relationship between discounting and abstinence. Previously we have shown that ex-smokers do not discount differently than non-smokers. Two hypotheses to explain that observation are (a) smokers who are successfully abstinent discounted less prior to the initiation of abstinence (less discounting leads to abstinence) and (b) abstinence leads to less discounting. These hypotheses may not be mutually exclusive. In Exp.4, we will examine whether individuals with proximate plans to quit cigarette smoking discount differently than both current smokers with no proximate plans to quit and ex-smokers. In Exp.5, we will follow up our initial observation regarding the effects of reinforced abstinence on discounting. Specifically, we propose to replicate and extend that observation with cigarette smokers by imposing and removing a contingency management procedure. If our prior work is replicated, then discounting should decrease when smoking abstinence is reinforced. We will extend that work by determining whether the decrease in discounting reverses when cigarette smokers relapse.