School of Psychology, Faculty of Science, University of New South Wales, Sydney NSW, Australia.
School of Pharmacy, Faculty of Life Sciences, University College London, London, England.
Ann Behav Med. 2019 Jan 1;53(1):16-28. doi: 10.1093/abm/kay011.
Recent evidence indicates that placebo effects can occur even when patients know that they are taking a placebo, termed the open-label placebo effect.
To assess whether placebo dose (one pill per day vs. four pills per day), treatment expectancies, and adherence contribute to open-label placebo effects.
Healthy undergraduate participants were randomly assigned to take one or four open-label placebo pills per day or to a no-treatment control group. Placebo-treated participants took a 5-day course of an open-label placebo described as enhancing physical (symptoms and sleep) and psychological (positive and negative emotional experience) well-being. Expectancies about placebo effectiveness and well-being were assessed at baseline, and well-being and adherence were assessed after the 5-day course of treatment.
Medium-to-large open-label placebo effects were evidenced in all well-being outcomes including sleep quality. Dose did not influence these effects. Both treatment expectancies and adherence were significant independent predictors of enhanced well-being in the two psychological well-being outcomes and the experience of physical symptoms, but sleep quality improved independently.
This is the first study to demonstrate the effect of open-label placebos in improving well-being and sleep quality and to show that open-label placebo reposes do not appear to be dose-dependent, but for most well-being outcomes are independently predicted by both positive expectancies and treatment adherence.
最近的证据表明，即使患者知道自己正在服用安慰剂，即所谓的开放性安慰剂效应，安慰剂效应也可能发生。
评估安慰剂剂量（每天一粒与每天四粒）、治疗预期和依从性是否有助于开放性安慰剂效应。
健康的本科生参与者被随机分配每天服用一粒或四粒开放性安慰剂，或接受无治疗对照。安慰剂治疗的参与者接受为期 5 天的开放性安慰剂治疗，该治疗被描述为增强身体（症状和睡眠）和心理（积极和消极情绪体验）健康。在基线时评估对安慰剂有效性和健康的预期，在 5 天治疗后评估健康和依从性。
在所有健康结果中，包括睡眠质量，都证明了中等至大的开放性安慰剂效应。剂量并不影响这些效果。治疗预期和依从性都是两个心理健康结果和身体症状体验中增强健康的显著独立预测因素，但睡眠质量独立改善。
这是第一项证明开放性安慰剂在改善幸福感和睡眠质量方面的作用的研究，并表明开放性安慰剂剂量似乎不是剂量依赖性的，但对于大多数健康结果，积极的预期和治疗依从性都可以独立预测。
