Pharmacological strategies for pain management have primarily focused on dampening ascending neurotransmission and on opioid receptor-mediated therapies. Little is known about the contribution of endogenous descending modulatory systems to clinical pain outcomes and why some patients are mildly affected while others suffer debilitating pain-induced dysfunctions. Placebo effects that arise from patients' positive expectancies and the underlying endogenous modulatory mechanisms may in part account for the variability in pain experience and severity, adherence to treatment, distinct coping strategies, and chronicity. Expectancy-induced analgesia and placebo effects in general have emerged as useful models to assess individual endogenous pain modulatory systems. Different systems and mechanisms trigger placebo effects that highly impact pain processing, clinical outcomes, and sense of well-being. This review illustrates critical elements of placebo mechanisms that inform the methodology of clinical trials, the discovery of new therapeutic targets, and the advancement of personalized pain management.

中文翻译：

---

疼痛疗法中的安慰剂作用。

疼痛治疗的药理策略主要集中在抑制上行神经传递和阿片受体介导的疗法上。关于内源性递减调节系统对临床疼痛预后的贡献以及为什么某些患者受到轻度影响而另一些患者则使衰弱性疼痛引起的功能障碍知之甚少。由患者的积极期望和潜在的内源性调节机制引起的安慰剂作用可能部分解释了疼痛经历和严重程度，对治疗的依从性，独特的应对策略以及慢性病的变异性。一般而言，预期诱导的镇痛和安慰剂作用已成为评估单个内源性疼痛调节系统的有用模型。不同的系统和机制会触发安慰剂效应，这些效应会严重影响疼痛的处理，临床结果和幸福感。这篇综述阐明了安慰剂机制的关键要素，这些要素为临床试验的方法，新的治疗靶标的发现以及个性化疼痛管理的发展提供了信息。