Pacific Parkinson's Research Centre, University of British Columbia, Vancouver, Canada.
Parkinsonism Relat Disord. 2009 Dec;15 Suppl 3:S72-4. doi: 10.1016/S1353-8020(09)70785-0.
Based on the observation that the placebo effect in Parkinson's disease was mediated by the release of endogenous dopamine in both the dorsal and ventral striatum, in 2002 we formally proposed the placebo-reward hypothesis. This hypothesis establishes a link between the placebo effect and reward mechanisms, and predicts that the activation of the ventral striatum should be present in any placebo response, in any medical condition. In keeping with this prediction, functional neuroimaging studies have shown placebo-induced activation of the reward circuitry in Parkinson's disease, depression, and pain. In fact, recent evidence suggests that the release of dopamine in the ventral striatum likely triggers the activation of the endogenous opioid system in placebo analgesia. The placebo-reward hypothesis also supports the notion that the expectation of clinical benefit plays a major role in the placebo effect. Probability and trust, two key factors involved in shaping expectations, must therefore be essential to the development of placebo responses. The ventral loop of the basal ganglia circuitry (anterior cingulate cortex-ventral striatum-ventral pallidum- mediodorsal nucleus of the thalamus -anterior cingulate cortex) is a fundamental component of the neuroanatomy of the placebo effect.
基于观察到帕金森病的安慰剂效应是通过背侧和腹侧纹状体中内源性多巴胺的释放介导的，我们于 2002 年正式提出了安慰剂奖励假说。该假说将安慰剂效应与奖励机制联系起来，并预测任何安慰剂反应，在任何医疗条件下，腹侧纹状体的激活都应该存在。与这一预测一致，功能神经影像学研究表明，在帕金森病、抑郁症和疼痛中，安慰剂会引起奖励回路的激活。事实上，最近的证据表明，腹侧纹状体中多巴胺的释放可能触发了内源性阿片系统在安慰剂镇痛中的激活。安慰剂奖励假说也支持这样一种观点，即对临床获益的期望在安慰剂效应中起着主要作用。因此，概率和信任，这两个参与塑造期望的关键因素，对于安慰剂反应的发展来说一定是必不可少的。基底神经节回路的腹侧环路（扣带回皮质-腹侧纹状体-腹侧苍白球-丘脑背内侧核-扣带回皮质）是安慰剂效应神经解剖学的一个基本组成部分。
