Accepted for/Published in: JMIR Research Protocols
Date Submitted: Mar 18, 2022
Open Peer Review Period: Mar 18, 2022 - May 13, 2022
Date Accepted: Mar 31, 2023
(closed for review but you can still tweet)
Warning: This is an author submission that is not peer-reviewed or edited. Preprints - unless they show as "accepted" - should not be relied on to guide clinical practice or health-related behavior and should not be reported in news media as established information.
Conditioning of the Cortisol Awakening Response: Study Protocol
ABSTRACT
Background:
The hormone cortisol plays important roles in human circadian and stress physiology and is an interesting target for interventions. Animal studies consistently show that cortisol is affected by pharmacological conditioning, but the results are mixed in humans. Cortisol also varies as part of a diurnal rhythm, showing a sharp increase right after awakening, the cortisol awakening response (CAR). Other studies have suggested that conditioning is also possible during sleep.
Objective:
We introduce a novel avenue for conditioning cortisol: by using the CAR as an unconditioned response and using scent conditioning while the participant is asleep. This study investigates an innovative way to study the effects of conditioning on cortisol and the diurnal rhythm, using a variety of devices and measures to make measurement possible at a distance and at unusual moments.
Methods:
The study protocol takes two weeks. Measures in week 1 are taken to reflect the CAR and waking under baseline conditions. For 3 consecutive nights in week 2, participants are exposed to a scent from 30min before awakening until their normal time of awakening. The scent thus becomes associated with the CAR. On the final night, participants are forced to wake four hours earlier, and either the same (conditioned group) or a different (control group) scent is presented half an hour before this new time. The primary outcome is the CAR, assessed by cortisol levels 0-45 minutes after awakening. Secondary outcomes are heart rate variability, actigraphy measures taken during sleep, and self-reported mood after awakening. To perform manipulations and measurements, the study uses wearable devices, online questionnaires and a programmed scent device.
Results:
Data collection is completed as of 24/12/2021.
Conclusions:
This study can provide new insights into learning effects on cortisol and the diurnal rhythm. If the procedure does affect the CAR and associated measures, it also has potential clinical significance in the treatment of sleep and stress disorders. Clinical Trial: Dutch Trial register (NTR), NL58792.058.16, registered 2019-06-07
Citation
Request queued. Please wait while the file is being generated. It may take some time.
Copyright
© The authors. All rights reserved. This is a privileged document currently under peer-review/community review (or an accepted/rejected manuscript). Authors have provided JMIR Publications with an exclusive license to publish this preprint on it's website for review and ahead-of-print citation purposes only. While the final peer-reviewed paper may be licensed under a cc-by license on publication, at this stage authors and publisher expressively prohibit redistribution of this draft paper other than for review purposes.