Delay Discounting and the Choice to Take a Drug

延迟折扣和服用药物的选择

• 批准号: 8144842
• 负责人: William L. Woolverton
• 金额: $ 29万
• 依托单位: UNIVERSITY OF MISSISSIPPI MED CTR
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-30 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8144842
• 关键词: Affect; Attention; Behavior; Behavioral; Cocaine; Dose; Drug abuse; Food; Goals; Human; Injection of therapeutic agent; Literature; Modeling; Monkeys; Nature; Outcome; Pharmaceutical Preparations; Psychological reinforcement; Relative (related person); Research; Rewards; Saccharin; Self Administration; Sucrose; Therapeutic; Time; Work; base; design; discount; discounting; drug abstinence; drug abuser; drug of abuse; human subject; interest; non-drug; public health relevance; reinforcer; research study; response

DESCRIPTION (provided by applicant): Delay between a behavior and its reinforcer usually decreases the subjective value of the reinforcer, a phenomenon termed delay discounting. There is a well-established quantitative model, the hyperbolic discounting function, which describes delay discounting. Research with delay discounting has made substantial theoretical contributions to our understanding of drug abuse. For example, drug abusers discount the value of drugs more rapidly than they do monetary reinforcers, suggesting that discounting rate may depend on the nature of the reinforcer. However, experiments comparing discounting of drugs and money have studied a single magnitude of each reinforcer in a hypothetical choice situation. In humans, magnitude of a delayed reinforcer is a crucial determinant of discounting rate. Research with non-humans is beginning to contribute to our understanding of the effects of delay on drug choice. Recently, we found that monkeys discounted non-drug reinforcers more steeply than they did cocaine, a result opposite to that observed in drug abusers. This difference may be due to the nature of the specific reinforcers studied, or to the use of real reinforcers with monkeys vs. hypothetical reinforcers with humans. Alternatively, it may be a consequence of differences in the relative magnitudes of the reinforcers. We propose to investigate the effect of reinforcer magnitude and delay on the rate of discounting of drug and non-drug reinforcers in monkeys given allomorphic (i.e., drug/non-drug) choices. Aim 1 is to establish dose-response functions for cocaine when the choice is between an immediate injection of cocaine and the delayed presentation of food. Discounting functions will be established for different amounts of food available with various delays. This allomorphic choice situation (i.e., immediate drug vs. delayed food) is analogous to the one underlying discounting interpretations of drug abuse: drug abusers are assumed to impulsively choose immediate drug reinforcers over larger, delayed non-drug reinforcers. Such allomorphic choice has received little study to date. Aim 2 is to establish magnitude-response functions for food when the choice is between the presentation of an immediate amount of food and a delayed injection of cocaine. Discounting functions will be established for different doses of cocaine available with various delays. This allomorphic choice situation is important because drug abuse also can involve choosing between more immediate non-drug reinforcers and delayed drug reinforcers, as exemplified by the fact that drug abusers often devote considerable time and effort to procuring drugs. This situation has received virtually no discussion in the discounting literature. Our hypotheses for both Aims are that the discounting of the delayed reinforcer will be well described by the hyperbolic function and that rate of discounting will vary inversely with the amount of the delayed reinforcer. The results will have important implications for understanding the determinants of drug choice and, potentially, for the use of delay to reinforcement in a therapeutic context. PUBLIC HEALTH RELEVANCE: Introducing a delay between a behavior and its consequence often weakens the behavior. Drug self- administration is a strongly maintained behavior, at least partially because of its immediate effects. The present project is designed to examine the choice between a drug injection and a non-drug reward to establish the extent to which both the magnitude of reward and the delay to reward determine the outcome of that choice. The results will enhance our understanding of behavioral approaches to decreasing the choice to take a drug of abuse.

描述（由申请人提供）：行为与其强化物之间的延迟通常会降低强化物的主观价值，这种现象称为延迟贴现。有一个完善的定量模型，即双曲贴现函数，它描述了延迟贴现。延迟折扣研究为我们对药物滥用的理解做出了重大的理论贡献。例如，吸毒者对药物价值的贴现速度比对货币强化物的贴现速度更快，这表明贴现率可能取决于强化物的性质。然而，比较药物和金钱折扣的实验研究了假设选择情况下每种强化物的单一量级。在人类中，延迟强化物的强度是贴现率的关键决定因素。对非人类的研究开始有助于我们理解延迟对药物选择的影响。最近，我们发现猴子对非药物强化剂的排斥程度比对可卡因的排斥程度更大，这一结果与在药物滥用者中观察到的结果相反。这种差异可能是由于所研究的特定强化物的性质，或者是由于对猴子使用真实的强化物与对人类使用假设的强化物。或者，这可能是增强物相对大小差异的结果。我们建议研究强化剂强度和延迟对给予异形（即药物/非药物）选择的猴子的药物和非药物强化剂贴现率的影响。目标 1 是在立即注射可卡因和延迟提供食物之间进行选择时，建立可卡因的剂量反应函数。将为不同数量的可用食物和不同的延迟建立折扣功能。这种异形选择情况（即立即药物与延迟食物）类似于药物滥用的一种潜在贴现解释：药物滥用者被认为会冲动地选择立即药物强化剂，而不是更大的、延迟的非药物强化剂。迄今为止，这种同质异形选择还很少受到研究。目标 2 是在立即提供食物和延迟注射可卡因之间进行选择时，建立食物的量级响应函数。将为不同剂量的可卡因建立折扣功能，并有不同的延迟。这种异形选择情况很重要，因为药物滥用还可能涉及在更直接的非药物强化剂和延迟药物强化剂之间进行选择，药物滥用者经常花费大量时间和精力来获取药物的事实就是例证。这种情况在贴现文献中几乎没有受到任何讨论。我们对这两个目标的假设是，延迟强化物的折扣将由双曲函数很好地描述，并且折扣率将与延迟强化物的数量成反比。这些结果对于理解药物选择的决定因素以及潜在地在治疗背景下使用延迟强化具有重要意义。 公共卫生相关性：在行为与其后果之间引入延迟通常会削弱该行为。自我给药是一种强烈维持的行为，至少部分是因为它的直接效果。本项目旨在检查药物注射和非药物奖励之间的选择，以确定奖励的大小和奖励的延迟在多大程度上决定该选择的结果。研究结果将增强我们对减少滥用药物选择的行为方法的理解。