Benson Sven, Elsenbruch Sigrid
Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
Front Psychiatry. 2019 Jul 17;10:511. doi: 10.3389/fpsyt.2019.00511. eCollection 2019.
Adverse side effects are reported by a large proportion of patients undergoing medical treatment in clinical practice or clinical trials. Nocebo effects, induced by negative treatment expectancies, can contribute to negative patient-reported outcomes but have rarely been studied in the context of inflammatory or immune-related conditions. Based on perceived treatment allocation, we herein analyzed nocebo responders in the placebo arms of randomized controlled double-blind experimental endotoxemia studies. We hypothesized that nocebo responders would report more bodily sickness symptoms and greater mood impairment. Out of = 106 participants who had all received placebo injection, = 20 (18.9%) wrongly believed they had received endotoxin and were thus considered as nocebo responders. Nocebo responders reported significantly more bodily sickness symptoms, suggesting that the perception of bodily symptoms affected perceived treatment allocation. Against our expectations, we did not find differences between nocebo responders and controls in psychological or physiological parameters. However, exploratory correlational analysis within nocebo responders revealed that more pronounced bodily sickness symptoms in response to placebo were associated with greater state anxiety and negative mood, as well as with the psychological traits catastrophizing and neuroticism. Our findings support that negative affectivity and personality-related factors may contribute to the reporting of sickness symptoms. Nonspecific symptoms experienced by patients undergoing pharmacological treatments or in randomized controlled trials can be misinterpreted and/or misattributed as unwanted side effects affecting perceived treatment allocation and presumably treatment satisfaction or its perceived efficacy. More nocebo research in the context of acute and chronic inflammatory conditions is warranted.
在临床实践或临床试验中，很大一部分接受治疗的患者报告了不良副作用。由消极治疗预期引发的反安慰剂效应可能导致患者报告负面结果，但在炎症或免疫相关疾病的背景下，这方面的研究很少。基于对治疗分配的认知，我们在此分析了随机对照双盲实验性内毒素血症研究中安慰剂组的反安慰剂反应者。我们假设反安慰剂反应者会报告更多身体不适症状和更严重的情绪受损情况。在106名均接受安慰剂注射的参与者中，20名（18.9%）错误地认为自己接受了内毒素，因此被视为反安慰剂反应者。反安慰剂反应者报告的身体不适症状明显更多，这表明身体症状的感知影响了对治疗分配的认知。与我们的预期相反，我们没有发现反安慰剂反应者与对照组在心理或生理参数上存在差异。然而，对反安慰剂反应者进行的探索性相关分析显示，对安慰剂产生更明显的身体不适症状与更高的状态焦虑和负面情绪相关，也与灾难化和神经质等心理特质相关。我们的研究结果支持消极情感和与人格相关的因素可能导致不适症状的报告。接受药物治疗的患者或在随机对照试验中出现的非特异性症状可能会被误解和/或错误归因于不良副作用，从而影响对治疗分配的认知，大概也会影响治疗满意度或其感知疗效。在急性和慢性炎症性疾病背景下进行更多的反安慰剂研究是有必要的。
