Institute of Psychology, Health, Medical and Neuropsychology unit, Leiden University, NL-2300 RB Leiden, The Netherlands.
Acta Derm Venereol. 2018 Feb 7;98(2):268-274. doi: 10.2340/00015555-2823.
Placebo effects are positive outcomes that are not due to active treatment components, which may be elicited even when patients are aware of receiving an inert substance (open-label). This proof-of-principle study investigated for the first time whether open-label placebo effects on itch can be induced by verbal suggestions alone. Ninety-two healthy volunteers were randomized to experimental (open-label suggestions) or control (no suggestions) groups. Self-reported itch evoked by histamine iontophoresis was the primary study outcome. In addition, itch expectations, skin condition and affect were assessed. The experimental group expected lower itch than the control group, which was, in turn, related to less experienced itch in this group only, although no significantly different itch levels were reported between groups. The results illustrate a potential role for open-label placebo effects in itch, and suggest that further study of verbal suggestions through an extensive explanation of placebo effects might be promising for clinical practice.
安慰剂效应是指并非由于积极治疗成分引起的积极结果，即使患者意识到正在接受无活性物质（开放性标签），也可能会产生这种效应。这项原理验证研究首次调查了单纯通过口头建议是否可以诱导瘙痒的开放性标签安慰剂效应。92 名健康志愿者被随机分配到实验组（开放性标签建议）或对照组（无建议）。组胺离子电渗疗法诱发的自我报告瘙痒是主要研究结果。此外，还评估了瘙痒预期、皮肤状况和情绪。实验组比对照组预期的瘙痒程度更低，而对照组的瘙痒程度与该组仅经历的瘙痒程度相关，尽管两组之间没有报告明显不同的瘙痒水平。结果表明开放性标签安慰剂效应在瘙痒中可能起作用，并提示通过广泛解释安慰剂效应进一步研究口头建议可能对临床实践有帮助。
