Is Ecstasy an Empathogen? Effects of MDMA on Social and Emotional Processing

描述（由申请人提供）：摇头丸是一种广泛使用的药物，据报道具有独特的效果，与其他兴奋剂不同；最值得注意的是，据说它能增加同理心和与他人的亲密感。这些所谓的对社会和情感处理的“情绪致病性”影响似乎促成了这种药物的广泛娱乐性使用，以及它作为心理治疗辅助工具的功效。摇头丸的主要精神活性成分是13,4-亚甲基二氧甲基苯丙胺（MDMA），它作用于血清素和多巴胺，这两种神经递质系统整体参与调节情感和奖励。在这个项目中，我们建议研究可能导致MDMA“情绪致病”效应的社会和情绪处理的维度。我们将研究MDMA（0、1.0和1.5mg/kg）对情绪识别和情绪反应的影响，这两个都是社会和情绪加工的核心方面，以及对社交能力的影响。在情绪识别的测量中，我们假设MDMA会减少对负面或威胁性情绪的识别，如恐惧、愤怒和悲伤。相反，我们期望MDMA能增强对积极物质的情绪反应。在社交性方面，我们假设药物会增强对社会目标友好和有吸引力的感知，并增加参与社会活动的动机。我们还将进行探索性调查，以确定MDMA主观和生理反应的个体差异的来源，包括与性别和选定基因型相关的差异。在一项单、双盲、安慰剂对照研究中，有摇头丸使用史的健康志愿者（N=100）将接受MDMA和两种有效对照药物甲基苯丙胺（MA; 20mg）和催产素（OT, 20iu）的测试。MA与MDMA有许多精神兴奋的特性，但似乎不会产生“情绪致病性”效应，而OT似乎产生了与MDMA相似的某些亲社会效应。这项提议的研究是高度创新的，因为它应用了社会神经科学的最新技术来研究药物奖励效应的过程（见McGregor et al., 2008; Schnur and Shurtleff, 2008）。这个项目将潜在地拓宽我们对药物如何与使用它们的社会和情感环境相互作用的看法，以及这些相互作用如何影响反复或强迫性使用这些药物的脆弱性。

DESCRIPTION (provided by applicant): Ecstasy is a widely used drug that reportedly has unique effects, distinct from other stimulants; most notably it is said to increase feelings of empathy and closeness to others. These so-called 'empathogenic' effects on social and emotional processing appear to contribute to the widespread recreational use of the drug, as well as its purported utility as an aid in psychotherapy. The main psychoactive constituent of ecstasy is 13,4- methylenedioxymethamphetamine (MDMA), which acts on serotonin and dopamine, two neurotransmitter systems integrally involved in modulation of affect and reward. In this project, we propose to investigate dimensions of social and emotional processing that may contribute to the putative 'empathogenic' effects of MDMA. We will study the effects of MDMA (0, 1.0 and 1.5mg/kg) on emotional recognition and emotional responsivity, both central aspects of social and emotional processing, and on sociability. On measures of emotional recognition, we hypothesize that MDMA will reduce recognition of negative or threatening emotions, such as fear, anger and sadness. Conversely, we expect MDMA to enhance emotional responsivity to positive material. On aspects of sociability, we hypothesize that the drug will enhance perception of social targets as friendly and attractive, and increase the motivation to engage in a social activity. We will also conduct exploratory investigations to identify sources of individual differences in subjective and physiological response to MDMA, including differences associated with gender and selected genotypes. In a single, double-blind, placebo controlled study, healthy volunteers (N=100) with a history of ecstasy use will be tested with MDMA and two active control drugs, methamphetamine (MA; 20mg) and oxytocin (OT, 20 IU). MA shares many psychostimulant properties with MDMA but does not appear to exert 'empathogenic' effects, whereas OT appears to produce certain pro-social effects that resemble those attributed to MDMA. The proposed study is highly innovative because it applies state-of-art techniques from social neuroscience to investigating processes involved in the rewarding effects of drugs (see McGregor et al., 2008; Schnur and Shurtleff, 2008). This project will potentially broaden our perspective on how drugs interact with the social and emotional context in which they are used, and how these interactions influence vulnerability to repeated or compulsive use of these drugs. PUBLIC HEALTH RELEVANCE: Ecstasy is a widely abused drug that appears to have unique psychological effects including feelings of empathy and closeness to others. This study will assess the effects of MDMA, the active drug in ecstasy, on both behavioral and subjective measures of emotional processing and sociability in humans. The study has implications for basic science to identify the brain circuits involved in social and emotional processing. It has public health implications by helping researchers understand why people use ecstasy, and some clinicians have suggested that MDMA might facilitate emotional processing during psychotherapy.