Page 80 - JCBP-2-2

Journal of Clinical and

Basic Psychosomatics

LETTER TO EDITOR
Stress and placebo effects: Two sides of the

same coin

Lei Cai*
Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders
(Ministry of Education), Collaborative Innovation Center of Genetics and Development, Shanghai
Jiaotong University, Shanghai, China

This letter aims to highlight the intricate relationship between stress and placebo
responses. A recent randomized, controlled, partially blinded study investigated the
interplay between acute experimental stress and placebo effects in nausea in 80 healthy
females aged 18 – 40. Participants susceptible to motion sickness, as determined
1
with the Motion Sickness Susceptibility Questionnaire, were screened for eligibility in
a structured telephone interview. Individuals meeting all inclusion criteria and none
of the exclusion criteria were randomized into two groups: (i) The stressful condition
group and (ii) the non-stressful condition group. The stressful condition group was
subjected to the Maastricht Acute Stress Test. These two groups were then randomly
subdivided to receive either placebo therapy or no treatment. The placebo therapy
contained a positive verbal suggestion of nausea improvement and transcutaneous
electrical nerve stimulation therapy. All participants underwent induced nausea with
a virtual optokinetic drum. Throughout the entire procedure, humoral, behavioral, and
psychophysiological parameters and response time estimation were repeatedly assessed.
Based on an objective parameter, specifically the normo-to-tachy (NTT) ratio, the
*Corresponding author: results indicated that experimentally-induced acute stress may interfere with the gastric
Lei Cai placebo effects, as the placebo effects were observed among non-stressed individuals
(lcai@sjtu.edu.cn) but not among stressed ones. The NTT ratio was utilized for nausea measurement of
Citation: Cai L. Stress and placebo gastric myoelectrical activities. Stress increased the NTT ratio in the untreated placebo
effects: Two sides of the same subgroup but not in the treated placebo subgroup. Furthermore, similar to these
coin. J Clin Basic Psychosom. findings, acute stress may interfere with the placebo effects on the estimated duration of
2024;2(2):1860.
https://doi.org/10.36922/jcbp.1860 induced nausea as the time passage was shorter among the placebo-untreated subgroup
but unchanged in the placebo-treated subgroup. While a shorter general time passage
Received: September 18, 2023
following placebo treatment was perceived among non-stressed individuals but not
Accepted: December 25, 2023 among stressed ones. However, the impact of acute stress on the placebo effect did not
Published Online: March 26, 2024 correspond to the other subjective symptoms (i.e., nausea and motion sickness), as it
was observed that placebo interventions exhibited consistent beneficial effects on nausea
Copyright: © 2024 Author(s).
1
This is an Open-Access article and motion sickness in non-stressed individuals compared to stressed individuals.
distributed under the terms of the These findings suggested that acute stress does not impede the placebo effects on the
Creative Commons Attribution subjective conscious evaluation of symptoms. However, it is important to note that the
License, permitting distribution,
and reproduction in any medium, experimentally induced acute stress might differ from real-life stress, possibly leading to
provided the original work is a misunderstanding among the participants. In addition, these results also indicated that
properly cited. there could be an association between stress and placebo effects, as conflicting results
2
Publisher’s Note: AccScience were observed pertaining to placebo effects on subjective symptoms with acute stress.
Publishing remains neutral with Therefore, ongoing research studying the impact of placebo on peripheral physiological
regard to jurisdictional claims in
published maps and institutional systems should also focus on elucidating the intricate relationship between stress and
affiliations. placebo responses within the context of mind-body interaction.

Volume 2 Issue 2 (2024) 1 https://doi.org/10.36922/jcbp.1860