Neural Correlates of Choices for Impulsive HIV-risk Behavior in Stimulant Dependence

 描述（由申请人提供）：非法兴奋剂使用和依赖性仍然是美国当今的重大问题（NIDA，2010年）。兴奋剂依赖者的两个主要健康问题是这一群体中性HIV风险行为的增加率和相应的HIV感染率增加（例如，Molitor等人，1999年）。虽然与艾滋病毒相关的性风险行为增加和兴奋剂依赖之间的关系已经得到了很好的建立，但选择从事危险性行为的决策过程并没有得到很好的描述。已知额顶叶边缘系统网络涉及延迟贴现任务中对即时和延迟结果的价值分配，该延迟贴现任务测量延迟奖励在延迟时如何失去其价值（麦克卢尔等人，2004，2007），并且兴奋剂依赖性参与者差异性地招募该网络（Monterosso等人，2007年）。的 最近开发的性折扣任务（约翰逊和布鲁纳，2012年，2013年）是一种衡量艾滋病毒风险的方法，类似于货币折扣任务，但评估了参与假设的风险性行为的决定如何作为延迟避孕套可用性的函数发生变化，从而获得安全性行为折扣率。我们收集的初步数据显示，可卡因依赖参与者的安全性行为折扣率远远高于非依赖对照组，男性也高于女性。拟议的研究将有助于照亮鲜为人知的决策过程中的性别和危险的性行为在兴奋剂依赖的参与者和控制直接比较BOLD反应使用功能磁共振成像在额顶叶边缘评估网络在决策过程中从事危险的性行为和延迟的钱。检查这些变量之间的相互作用效应将使我们能够确定是否依赖于安全性行为折扣率的影响取决于性别（反之亦然），或者这些因素是否独立地影响决策。我们建议比较折扣率和相关的大脑激活的性别折扣和货币折扣任务的可卡因依赖与控制（具体目标1）和男性和女性之间（具体目标2），以及这些之间的相互作用。我们将使用fMRI测量BOLD反应，同时参与者在立即危险性行为和延迟不同时间的安全性行为之间做出选择。我们还将探讨危险的性行为和种族在探索性目标中的作用。总之，这些目标将解决决策过程潜在的危险性行为在兴奋剂使用者和非兴奋剂使用者，并可以告知未来的研究，以预测，预防和治疗危险性行为在兴奋剂依赖和非依赖人群。

 DESCRIPTION (provided by applicant): Illicit stimulant use and dependence remain significant problems in the United States today (NIDA, 2010). Two of the major health concerns with stimulant dependent individuals is the increased rate of sexual HIV-risk behavior in this group and a corresponding increased rate of HIV infection (e.g., Molitor et al., 1999). While the relationship between increased HIV-related sexual risk behavior and stimulant dependence is well established, the decision making processes that underlies the choice to engage in risky sex is not well characterized. A fronto-parietal-limbic network is known to be involved the assignment of value to immediate and delayed outcomes in delayed discounting tasks that measure how delayed rewards lose their value when delayed (McClure et al., 2004, 2007), and stimulant-dependent participants differentially recruit this network (Monterosso et al., 2007). The recently developed sexual discounting task (Johnson & Bruner, 2012, 2013) is a measure of HIV risk that is similar to a monetary discounting task, but assesses how the decision to engage in hypothetical risky sex changes as a function of the delay to condom availability, thereby obtaining a safe-sex discount rate. We have collected preliminary data showing that safe-sex discount rates are much higher in cocaine-dependent participants than non-dependent controls, as well as in males compared to females. The proposed research will help illuminate the poorly understood decision-making processes about gender and risky sex in stimulant-dependent participants and controls by directly comparing BOLD response using fMRI in fronto-parietal-limbic valuation networks during decisions about engaging in risky sex and delayed money. Examining interaction effects between these variables will allow us to determine whether the effect of stimulant dependence on safe-sex discount rates depends on gender (or vice versa), or if these factors affect decision- making independently. We propose to compare discount rates and associated brain activation of the sex discounting and monetary discounting tasks in cocaine dependence vs controls (Specific Aim 1) and between males and females (Specific Aim 2), and the interaction between these. We will measure BOLD response using fMRI while participants make choices between immediate risky sex and safer sex that is delayed by various durations of time. We will also explore the role of risky sexual practices and race in an Exploratory Aim. Together, these aims will address the decision-making processes underlying risky sexual behavior in both stimulant users and non-stimulant users, and could inform future research to predict, prevent, and treat risky sexual behavior in both stimulant-dependent and non-dependent populations.