Effects of Open-Label Placebos on State Anxiety and Glucocorticoid Stress Responses.

Michael Schaefer,Julian Hellmann-Regen,Sören Enge

doi:10.3390/brainsci11040508

Abstract

Stress belongs to the most frequent negative feelings people are confronted with in daily life. Strategies against acute stress include, e.g., relaxation techniques or medications, but it is also known that placebos can successfully reduce negative emotional stress. While it is widely held that placebos require deception to provoke a response, recent studies demonstrate intriguing evidence that placebos may work even without concealment (e.g., against anxiety or pain). Most of these studies are based on self-report questionnaires and do not include physiological measures. Here we report results of a study examining whether placebos without deception reduce acute stress. A total of 53 healthy individuals received either placebos without deception or no pills before participating in a laboratory stress test (Maastricht Acute Stress Test, MAST). We recorded self-report stress measures and cortisol responses before and after the MAST. Results showed no significant differences between the placebo and the control group, but when comparing participants with high relative to low beliefs in the power of placebos we found significant lower anxiety and cortisol responses for the placebo believers. These results show that non-deceptive placebos may successfully reduce acute anxiety and stress, but only in participants who had a strong belief in placebos. We discuss the results by suggesting that open-label placebos might be a possible treatment to reduce stress at least for some individuals.

Highlights

When we are exposed to a threatening situation, our brain activates two physiological systems in order to cope with this stressful event, the autonomic nervous system (ANS) and the hypothalamic–pituitary–adrenal (HPA) axes
An ANOVA for stress and anxiety measured with the STAI-S showed an effect for time (F(2, 102) = 3.00, p = 0.066, Greenhouse Geisser correction), but no interaction with group (F(2, 102) = 0.41, p > 0.10)
PANAS scores for mood and anxiety increased during stress for both groups but failed to reach the level of significance

Summary

Introduction

When we are exposed to a threatening situation, our brain activates two physiological systems in order to cope with this stressful event, the autonomic nervous system (ANS) and the hypothalamic–pituitary–adrenal (HPA) axes. While the ANS stimulates the secretion of adrenalin and noradrenaline (resulting in increased arousal and attention), the activation of the HPA system results in releasing glucocorticoid cortisol [1,2]. The role of these two systems varies depending on the intensity and type of stress (for example, psychological vs physiological stress). There are different strategies to cope with stressful events, including, for example, cognitive–behavioral skills training, yoga, massage, mindfulness-based interventions, and medication [3,4,5,6]. Medications may be antidepressants or, to reduce acute stress, benzodiazepines or other GABA (Gamma aminobutyric acid)-like substances, which are known to be linked to the risk of addiction [7]

Methods

Results

Conclusion