Elsenbruch Sigrid, Roderigo Till, Enck Paul, Benson Sven
Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, Essen, Germany.
Department of Internal Medicine VI, University Hospital Tuebingen, Tuebingen, Germany.
Front Psychiatry. 2019 Mar 21;10:144. doi: 10.3389/fpsyt.2019.00144. eCollection 2019.
Translational research aiming to elucidate mediators and moderators of placebo and nocebo effects is highly relevant. This experimental study tested effects of a brief progressive muscle relaxation (PMR) exercise, designed to alter psychobiological stress parameters, on the magnitude of placebo and nocebo effects in a standardized psychosocial treatment context. In 120 healthy volunteers (60 men, 60 women), pain expectation, pain intensity, and pain unpleasantness in response to individually-calibrated rectal distensions were measured with visual analog scales during a baseline. Participants were then randomized to exercise PMR (relaxation group: = 60) or a simple task (control group: = 60), prior to receiving positive (placebo), negative (nocebo) or neutral suggestions regarding an intravenous administration that was in reality saline in all groups. Identical distensions were repeated (test). State anxiety, salivary cortisol, heart rate, and blood pressure were assessed repeatedly. Data were analyzed using analysis of covariance, planned Bonferroni-corrected group comparisons, as well as exploratory correlational and mediation analyses. Treatment suggestions induced group-specific changes in pain expectation, with significantly expectation in placebo and expectation in nocebo groups. PMR had no discernable effect on pain expectation, state anxiety or cortisol, but led to significantly lower heart rate and systolic blood pressure. Relaxation significantly interacted with positive treatment suggestions, which only induced placebo analgesia in relaxed participants. No effects of negative suggestions were found in planned group comparisons, irrespective of relaxation. Exploratory correlation and mediation analyses revealed that pain expectation was a mediator to explain the association between treatment suggestions and pain-related outcomes. Clearly, visceral pain modulation is complex and involves many cognitive, emotional, and possibly neurobiological factors that remain to be fully understood. Our findings suggest that a brief relaxation exercise may facilitate the induction of placebo analgesia by positive when compared to neutral treatment suggestions. They underscore the contribution of relaxation and stress as psychobiological states within the psychosocial treatment context-factors which clearly deserve more attention in translational studies aiming to maximize positive expectancy effects in clinical settings.
旨在阐明安慰剂和反安慰剂效应的介导因素和调节因素的转化研究具有高度相关性。这项实验研究测试了一种简短的渐进性肌肉放松（PMR）练习对标准化社会心理治疗环境中安慰剂和反安慰剂效应大小的影响，该练习旨在改变心理生理应激参数。在120名健康志愿者（60名男性，60名女性）中，在基线期间使用视觉模拟量表测量了对个体校准的直肠扩张的疼痛预期、疼痛强度和疼痛不适感。然后，参与者被随机分为进行PMR练习（放松组：n = 60）或简单任务（对照组：n = 60），之后在所有组中接受关于静脉注射的积极（安慰剂）、消极（反安慰剂）或中性建议，而实际上所有组注射的都是生理盐水。重复相同的扩张（测试）。反复评估状态焦虑、唾液皮质醇、心率和血压。使用协方差分析、计划的Bonferroni校正组比较以及探索性相关和中介分析对数据进行分析。治疗建议在疼痛预期方面引起了组特异性变化，安慰剂组的预期显著增加，反安慰剂组的预期降低。PMR对疼痛预期、状态焦虑或皮质醇没有明显影响，但导致心率和收缩压显著降低。放松与积极治疗建议有显著交互作用，积极治疗建议仅在放松的参与者中诱导出安慰剂镇痛作用。在计划的组比较中未发现消极建议有任何影响，无论是否放松。探索性相关和中介分析表明，疼痛预期是解释治疗建议与疼痛相关结果之间关联的一个中介因素。显然，内脏痛调制是复杂的，涉及许多认知、情感以及可能还有神经生物学因素，这些因素仍有待充分理解。我们的研究结果表明，与中性治疗建议相比，简短的放松练习可能会促进积极治疗建议诱导安慰剂镇痛作用。它们强调了放松和压力作为社会心理治疗环境中的心理生理状态的作用——在旨在最大化临床环境中积极预期效应的转化研究中，这些因素显然值得更多关注。
