Watkinson Andrew, Chapman Sarah C E, Horne Rob
Centre for Behavioural Medicine, Department of Practice and Policy, UCL School of Pharmacy, University College London, London, United Kingdom.
Centre for Behavioural Medicine, Department of Practice and Policy, UCL School of Pharmacy, University College London, London, United Kingdom.
J Pain. 2017 Aug;18(8):908-922. doi: 10.1016/j.jpain.2017.02.435. Epub 2017 Mar 7.
This study examined whether placebo responses were predicted by a theoretical model of specific and general treatment beliefs. Using a randomized crossover, experimental design (168 healthy individuals) we assessed whether responses to a cold pressor task were influenced by 2 placebo creams described as pharmaceutical versus natural. We assessed whether placebo responses were predicted by pretreatment beliefs about the treatments (placebo) and by beliefs about the pain. The efficacy of pharmaceutical as well as natural placebos in reducing pain intensity was predicted by aspects of pain catastrophizing including feelings of helplessness (pharmaceutical: B = .03, P < .01, natural: B = .02, P < .05) and magnification of pain (pharmaceutical: B = .04, P < .05, natural: B = .05, P < .05) but also by pretreatment necessity beliefs (pharmaceutical: B = .21, P < .01, natural: B = .16, P < .05) and, for the pharmaceutical condition, by more general beliefs about personal sensitivity to pharmaceuticals (B = .14, P < .05). Treatment necessity beliefs also partially mediated the effects of helplessness on placebo responses. Treatment necessity beliefs for the pharmaceutical placebo were influenced by general pharmaceutical beliefs whereas necessity beliefs for the natural placebo were informed by general background beliefs about holistic treatments. Our findings show that treatment beliefs influence the placebo effect suggesting that they may offer an additional approach for understanding the placebo effect.
Placebo effects contribute to responses to active analgesics. Understanding how beliefs about different types of treatment influence placebo analgesia may be useful in understanding variations in treatment response. Using the cold pressor paradigm we found that placebo analgesia was influenced by beliefs about natural remedies, pharmaceutical medicines, and about pain.
本研究考察了特定和一般治疗信念的理论模型是否能预测安慰剂反应。采用随机交叉实验设计（168名健康个体），我们评估了对冷加压任务的反应是否受到两种分别描述为药物性与天然性的安慰剂乳膏的影响。我们评估了安慰剂反应是否可通过对治疗（安慰剂）的预处理信念以及对疼痛的信念来预测。药物性和天然性安慰剂在减轻疼痛强度方面的效果可通过灾难化思维的某些方面来预测，包括无助感（药物性：B = 0.03，P < 0.01；天然性：B = 0.02，P < 0.05）和疼痛放大（药物性：B = 0.04，P < 0.05；天然性：B = 0.05，P < 0.05），但也可通过预处理必要性信念（药物性：B = 0.21，P < 0.01；天然性：B = 0.16，P < 0.05）来预测，并且对于药物性情况，还可通过对个人对药物敏感性的更一般信念来预测（B = 0.14，P < 0.05）。治疗必要性信念也部分介导了无助感对安慰剂反应的影响。药物性安慰剂的治疗必要性信念受一般药物信念的影响，而天然性安慰剂的必要性信念则受关于整体治疗的一般背景信念的影响。我们的研究结果表明，治疗信念会影响安慰剂效应，这表明它们可能为理解安慰剂效应提供一种额外的方法。
安慰剂效应有助于对活性镇痛药的反应。了解对不同类型治疗的信念如何影响安慰剂镇痛作用，可能有助于理解治疗反应的差异。使用冷加压范式，我们发现安慰剂镇痛作用受到对天然疗法、药物以及疼痛的信念的影响。
