Morton Debora L, El-Deredy Wael, Jones Anthony K P
Human Pain Research Group, Institute of Brain, Behaviour and Mental Health, University of Manchester, Salford, UK.
Handb Exp Pharmacol. 2014;225:71-80. doi: 10.1007/978-3-662-44519-8_4.
Placebo analgesia has become a well-studied phenomenon that encompasses psychology, physiology and pharmacology. In this chapter we explore the complex interactions between these disciplines in order to argue that the placebo response is more than a simple change in perception but is a cognitive style driven by prior expectations. The expectation of treatment effect is shaped by prior information and prior experience which our brain uses to predict future events. In the case of placebo analgesia the prediction of pain relief overrules the actual feeling of pain leading to a decrease in pain sensation. This altered sensation can be attributed to personality traits, altered error monitoring processes, changes in anticipatory responses to pain and activation of the endogenous opioid system. In conclusion we discuss how altered sensory processing by descending pain modulation may play a part in placebo analgesia and how the loss of the brains prefrontal regions can make it impossible to have a placebo response.
安慰剂镇痛已成为一个经过充分研究的现象，它涵盖心理学、生理学和药理学。在本章中，我们探讨这些学科之间的复杂相互作用，以论证安慰剂反应不仅仅是感知上的简单变化，而是一种由先前预期驱动的认知方式。治疗效果的预期由先前信息和先前经验塑造，我们的大脑利用这些来预测未来事件。在安慰剂镇痛的情况下，对疼痛缓解的预测压倒了实际的疼痛感觉，导致疼痛感减轻。这种感觉的改变可归因于人格特质、错误监测过程的改变、对疼痛的预期反应的变化以及内源性阿片系统的激活。最后，我们讨论下行疼痛调制如何改变感觉处理可能在安慰剂镇痛中起作用，以及大脑前额叶区域的丧失如何可能导致无法产生安慰剂反应。
