Jagiellonian University, Institute of Psychology, Pain Research Group, Kraków, Poland.
Doctoral School in the Social Sciences, Jagiellonian University, Kraków, Poland.
Pain. 2024 Jul 1;165(7):1605-1612. doi: 10.1097/j.pain.0000000000003161. Epub 2024 Jan 16.
Previous research has indicated that an open-label placebo can reduce pain in both healthy participants and patients with chronic pain. Because nondeceptive placebos seem to be an effective and more ethical alternative to deceptive placebos, optimizing this kind of treatment is essential. Observational learning was previously shown to induce the deceptive placebo effect; therefore, this study aimed to verify its effectiveness in fortifying the open-label placebo effect. Healthy volunteers (N = 117) were randomly assigned to 4 groups: open-label placebo with observational learning (OLP + OBL), open-label placebo (OLP), deceptive placebo with observational learning (OBL), or control group. Participants underwent baseline and testing measurements, during which they self-reported pain induced by heat stimulation. Between assessments, placebo cream was openly administered in the OLP and OLP + OBL groups. The OLP + OBL group next watched a model experiencing hypoalgesia after cream application. In the OBL group, participants received placebo cream with no information about its effect, and then they watched the model. The placebo effect was successfully evoked in all experimental groups (OLP + OBL, OLP, and OBL), which confirms the effectiveness of both open-label and deceptive placebo interventions for pain reduction. However, the hypoalgesic effect was of similar magnitude in the OLP and OLP + OBL groups, which indicates that observation did not contribute to the effect. The results showed that reinforcing the open-label placebo by observational learning may be redundant, but more research is needed to confirm these findings.
先前的研究表明，开放标签安慰剂可减轻健康参与者和慢性疼痛患者的疼痛。由于非欺骗性安慰剂似乎是欺骗性安慰剂的有效且更符合伦理的替代方法，因此优化这种治疗方法至关重要。先前的观察性学习表明可以诱导欺骗性安慰剂效应；因此，本研究旨在验证其在增强开放标签安慰剂效应方面的有效性。将健康志愿者（N=117）随机分为 4 组：具有观察性学习的开放标签安慰剂（OLP+OBL）、开放标签安慰剂（OLP）、具有观察性学习的欺骗性安慰剂（OBL）或对照组。参与者接受基线和测试测量，在此期间他们自我报告了热刺激引起的疼痛。在评估之间，在 OLP 和 OLP+OBL 组中公开给予安慰剂乳膏。OLP+OBL 组随后观看了模型在涂抹乳膏后出现的痛觉减退。在 OBL 组中，参与者接受了没有关于其效果信息的安慰剂乳膏，然后他们观看了模型。在所有实验组（OLP+OBL、OLP 和 OBL）中均成功诱发了安慰剂效应，这证实了开放标签和欺骗性安慰剂干预对减轻疼痛的有效性。然而，OLP 和 OLP+OBL 组的镇痛效果相似，这表明观察并未对效果产生影响。结果表明，通过观察性学习来增强开放标签安慰剂可能是多余的，但需要进一步的研究来证实这些发现。
