Institute of Medical Psychology, Medical Faculty, LMU Munich, 80336, Munich, Germany.
Wessex Neurological Centre, University Hospital Southampton and Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, SO16 6YD, UK.
Sci Rep. 2023 Jun 19;13(1):9908. doi: 10.1038/s41598-023-36296-w.
Nausea often occurs in stressful situations, such as chemotherapy or surgery. Clinically relevant placebo effects in nausea have been demonstrated, but it remains unclear whether stress has an impact on these effects. The aim of this experimental study was to investigate the interplay between acute stress and placebo effects in nausea. 80 healthy female volunteers susceptible to motion sickness were randomly assigned to either the Maastricht Acute Stress Test or a non-stress control condition, and to either placebo treatment or no treatment. Nausea was induced by a virtual vection drum and behavioral, psychophysiological as well as humoral parameters were repeatedly assessed. Manipulation checks confirmed increased cortisol levels and negative emotions in the stressed groups. In the non-stressed groups, the placebo intervention improved nausea, symptoms of motion sickness, and gastric myoelectrical activity (normo-to-tachy (NTT) ratio). In the stressed groups, the beneficial effects of the placebo intervention on nausea and motion sickness remained unchanged, whereas no improvement of the gastric NTT ratio was observed. Results suggest that placebo effects on symptoms of nausea and motion sickness are resistant to experimentally-induced stress. Stress most likely interfered with the validity of the gastric NTT ratio to measure nausea and thus the gastric placebo effect.
恶心通常发生在紧张的情况下，如化疗或手术。已经证明了临床上相关的恶心安慰剂效应，但目前尚不清楚压力是否会对这些效应产生影响。本实验研究的目的是调查恶心的急性应激和安慰剂效应之间的相互作用。80 名易患运动病的健康女性志愿者被随机分配到马斯特里赫特急性应激测试或非应激对照条件，以及安慰剂治疗或不治疗。通过虚拟运动晕机鼓来诱导恶心，并反复评估行为、心理生理和体液参数。操作检查证实，应激组的皮质醇水平和负面情绪增加。在非应激组中，安慰剂干预改善了恶心、晕机症状和胃肌电活动（正常到心动过速[NTT] 比值）。在应激组中，安慰剂干预对恶心和晕机症状的有益影响保持不变，而胃 NTT 比值没有改善。结果表明，安慰剂对恶心和晕机症状的影响不受实验性应激的影响。压力很可能干扰了胃 NTT 比值测量恶心的有效性，从而干扰了胃安慰剂效应。
