Conditioning cortisol in healthy young women – A randomized controlled trial

Judith Tekampe,Henriët Van Middendorp,Nienke R Biermasz,Fred C.G.J Sweep,Onno C Meijer,Iris C.M Pelsma,Alberto M Pereira,Ad R.M.M Hermus,Andrea W.M Evers

doi:10.1016/j.psyneuen.2020.105081

Abstract

BackgroundLearned placebo effects induced by pharmacological conditioning affect immune and endocrine outcomes and may offer new possibilities for clinical applications. Whether or not cortisol is subject to this type of associative learning processes, and whether conditioning may affect responses to stress, is currently unclear. MethodA randomized placebo-controlled trial was conducted in 48 healthy young women. During acquisition, participants received a pill containing either 100 mg hydrocortisone (unconditioned stimulus) or placebo, paired with a gustatory conditioned stimulus on three consecutive days. During evocation, all participants received placebo paired with the conditioned stimulus, again on three consecutive days. During the third evocation trial, participants underwent a psychosocial stress task. The main outcome parameter salivary cortisol and secondary outcome parameters salivary alpha-amylase, self-reported positive affect and tension, heart rate, and skin conductance level were measured at several time points. ResultsSignificant baseline group differences on cortisol were found at several time points, which complicate the interpretation of group differences. During the first evocation session, the conditioned group showed a moderately smaller cumulative decrease in salivary cortisol from baseline than the placebo control group. No significant differences were found between the groups on cortisol during the second and third evocation or in response to stress, nor on other outcome measures. ConclusionAlthough the results provide potential further indications for effects of conditioning on cortisol, baseline differences make it impossible to draw clear conclusions. No indications for possible effects of conditioning on the cortisol stress response or autonomous or affective responses to stress were found.

Highlights

Learned placebo effects can be induced by repeatedly pairing a pharmacologically salient unconditioned stimulus (UCS) with a previ ously neutral conditioned stimulus (CS) in a classical conditioning paradigm
As cortisol plays a key role in the regulation of the stress response, conditioned cortisol responses would be of great conceptual interest and possibly clinical relevance
The current study set out to investigate whether cortisol can be conditioned in healthy young women by repeatedly pairing the administration of hydrocortisone with a gustatory conditioned stimulus (CS)

Summary

Introduction

Learned placebo effects can be induced by repeatedly pairing a pharmacologically salient unconditioned stimulus (UCS) with a previ ously neutral conditioned stimulus (CS) in a classical conditioning paradigm. Learned placebo effects induced by pharmacological conditioning affect immune and endocrine outcomes and may offer new possibilities for clinical applications. Whether or not cortisol is subject to this type of associative learning processes, and whether conditioning may affect responses to stress, is currently unclear. Participants received a pill containing either 100 mg hydrocortisone (unconditioned stimulus) or placebo, paired with a gustatory conditioned stimulus on three consecutive days. All participants received placebo paired with the conditioned stimulus, again on three consecutive days. No signif icant differences were found between the groups on cortisol during the second and third evocation or in response to stress, nor on other outcome measures. No indications for possible effects of condi tioning on the cortisol stress response or autonomous or affective responses to stress were found

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Results

Conclusion