Giordano Louis A, Bickel Warren K, Loewenstein George, Jacobs Eric A, Marsch Lisa, Badger Gary J
Department of Psychiatry, University of Vermont, Burlington, VT 05401, USA.
Psychopharmacology (Berl). 2002 Sep;163(2):174-82. doi: 10.1007/s00213-002-1159-2. Epub 2002 Jul 13.
A growing literature suggests that excessive temporal discounting of delayed rewards may be a contributing factor in the etiology of substance abuse problems. Little is known, however, about how drug deprivation may affect temporal discounting of delayed rewards by drug-dependent individuals.
To examine the extent to which opioid deprivation affects how opioid-dependent individuals discount small, medium and large quantities of delayed heroin and money.
Thirteen opioid-dependent individuals maintained on buprenorphine completed a hypothetical choice task in which they choose between a constant delayed reward amount and an immediate reward amount that was adjusted until they expressed indifference between both outcomes. The task was completed for three values of heroin and money rewards during eight sessions under conditions of opioid deprivation (four sessions) and satiation (four sessions).
Across conditions, hyperbolic functions provided a good fit for the discounting data. Degree of discounting was significantly higher when subjects were opioid deprived. Consistent with previous findings, degree of discounting was higher for heroin than money and inversely related to the magnitude of the reward.
Opioid deprivation increased the degree to which dependent individuals discounted delayed heroin and money. Understanding the conditions that affect how drug-dependent individuals discount delayed rewards might help us understand the myopic choices made by such individuals and help improve treatment outcomes.
越来越多的文献表明，对延迟奖励的过度时间折扣可能是物质滥用问题病因的一个促成因素。然而，对于药物戒断如何影响药物依赖个体对延迟奖励的时间折扣，人们知之甚少。
研究阿片类药物戒断在多大程度上影响阿片类药物依赖个体对少量、中等量和大量延迟海洛因及金钱的折扣。
13名维持丁丙诺啡治疗的阿片类药物依赖个体完成了一项假设选择任务，在该任务中，他们要在一个固定的延迟奖励量和一个即时奖励量之间进行选择，即时奖励量会不断调整，直到他们对两种结果表现出无差异。在阿片类药物戒断（四个疗程）和满足（四个疗程）的条件下，在八个疗程中针对海洛因和金钱奖励的三个值完成该任务。
在所有条件下，双曲线函数都能很好地拟合折扣数据。当受试者处于阿片类药物戒断状态时，折扣程度显著更高。与先前的研究结果一致，海洛因的折扣程度高于金钱，且与奖励幅度呈负相关。
阿片类药物戒断增加了依赖个体对延迟海洛因和金钱的折扣程度。了解影响药物依赖个体对延迟奖励进行折扣的条件，可能有助于我们理解此类个体做出的短视选择，并有助于改善治疗效果。
