Our understanding and conceptualization of the placebo effect has shifted in emphasis from a focus on the inert content of a physical placebo agent to the overall simulation of a therapeutic intervention. Research has identified many types of placebo responses driven by different mechanisms depending on the particular context wherein the placebo is given. Some placebo responses, such as analgesia, are initiated and maintained by expectations of symptom change and changes in motivation/emotions. Placebo factors have neurobiological underpinnings and actual effects on the brain and body. They are not just response biases. Other placebo responses result from less conscious processes, such as classical conditioning in the case of immune, hormonal, and respiratory functions. The demonstration of the involvement of placebo mechanisms in clinical trials and routine clinical practice has highlighted interesting considerations for clinical trial design and opened up opportunities for ethical enhancement of these mechanisms in clinical practice.

中文翻译：

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安慰剂作用的全面综述：最新进展和当前想法。

我们对安慰剂作用的理解和概念化的重点已经从对物理安慰剂惰性含量的关注转向对治疗干预的整体模拟。研究已经确定了多种类型的安慰剂反应，这些机制是由不同的机制决定的，具体取决于给定安慰剂的具体情况。一些安慰剂的反应，例如镇痛，是通过对症状变化和动机/情绪变化的期望而引发和维持的。安慰剂因子具有神经生物学基础，并且对大脑和身体有实际作用。它们不只是回应偏见。其他安慰剂反应是由意识较弱的过程引起的，例如免疫，激素和呼吸功能方面的经典条件。