Altered striatal reward processing in abstinent dependent cannabis users: Social context matters
Altered striatal reward processing in abstinent dependent cannabis users: Social context matters
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戒断依赖大麻使用者纹状体奖励处理的改变：社会背景很重要
DOI：
10.1016/j.euroneuro.2019.01.106
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发表时间：
2019
影响因子：
5.6
通讯作者：
Becker Benjamin
中科院分区：
文献类型：
--
作者：
Zimmermann Kaeli;Kendrick Keith M.;Scheele Dirk;Dau Wolfgang;Banger Markus;Maier Wolfgang;Weber Bernd;Ma Yina;Hurlemann Rene;Becker Benjamin
公众认为大麻相对无害，加上声称的医疗好处，导致了大麻合法化的行动。然而，对大麻依赖的长期后果，以及它们是否与其他毒品有质的不同，人们仍然知之甚少。成瘾药物的一个关键特征是，长期使用会导致纹状体奖赏过程的适应，削弱对物质本身和自然(非毒品)奖赏的反应性。在此背景下，本研究调查了23名戒烟者和24名匹配的不使用大麻的对照组的大麻依赖是否与对社会奖励的行为和神经反应的持久变化有关。在人际愉悦触摸fMRI范式中，参与者被引导相信他们处于男性或女性实验者(男性，女性)的身体接近或触摸(亲密，触摸)中，允许上下文调节感知的愉悦和相关的神经反应。与男性相比，女性与男性相比，依赖大麻的人与健康对照组相比，快感体验的增加显著减弱。与男性相比，控制组对女性的反应是纹状体激活增加，而大麻使用者表现出相反的激活模式，更强的变化与更高的终生大麻暴露相关。在依赖大麻的人中，对愉悦触觉的神经处理被发现是完整的。这些发现表明，大麻依赖与纹状体对非药物奖励的钝化加工有关，并表明这些变化可能导致社会加工缺陷。
Public perception of cannabis as relatively harmless, alongside claimed medical benefits, have led to moves towards its legalization. Yet, long-term consequences of cannabis dependence, and whether they differ qualitatively from other drugs, are still poorly understood. A key feature of addictive drugs is that chronic use leads to adaptations in striatal reward processing, blunting responsivity to the substance itself and natural (non-drug) rewards. Against this background, the present study investigated whether cannabis dependence is associated with lasting alterations in behavioral and neural responses to social reward in 23 abstinent cannabis-dependent men and 24 matched non-using controls. In an interpersonal pleasant touch fMRI paradigm, participants were led to believe they were in physical closeness of or touched (CLOSE, TOUCH) by either a male or female experimenter (MALE, FEMALE), allowing contextual modulation of the perceived pleasantness and associated neural responses. Upon female compared to male touch, dependent cannabis users displayed a significantly attenuated increase of pleasantness experience compared to healthy controls. Controls responded to female as compared to male interaction with increased striatal activation whereas cannabis users displayed the opposite activation pattern, with stronger alterations being associated with a higher lifetime exposure to cannabis. Neural processing of pleasant touch in dependent cannabis users was found to be intact. These findings demonstrate that cannabis dependence is linked to blunted striatal processing of non-drug rewards and suggest that these alterations may contribute to social processing deficits.