Oxytocin and the Processing of Social Stress-Associated Chemosignals

Phase 1

Completed

• Conditions: Healthy Volunteers
• Interventions: Drug: Placebo; Drug: Oxytocin

• Registration Number: NCT03265899
• Lead Sponsor: University Hospital, Bonn

Brief Summary

The purpose of this study is to determine whether oxytocin modulates the processing of stress-associated chemosignals and which substrates are involved.

Detailed Description

Social transmission of stress and fear is not restricted to visual or auditory cues, but extends to the olfactory domain, a phylogenetically more ancient sense. Exposure to axillary sweat from healthy volunteers undergoing an emotional stressor task evokes a strong vicarious stress response on the behavioral and neural level.Particularly, anxious individuals have been shown to exhibit a heightened sensitivity to social chemosensory stress cues (axillary sweat). The neuropeptide oxytocin (OXT) exerts anxiolytic and anti-stress effects in visual and auditory modalities, however, it still elusive whether OXT also modulates the processing of stress-associated chemosignals. Axillary sweat were obtained from an unrelated sample of 30 healthy men undergoing the Trier Social Stress Test and ergometer training as control.Subsequently, subjects completed a forced-choice emotional face recognition task composed of stimuli with varying intensities (neutral to fearful), while they were exposed to both sweat stimuli and a non-social control odor (raspberry) after OXT or placebo administration, respectively. The investigators expect that OXT selectively diminishes chemosensory-induced behavioral biases and neural responses to stress-related odors.

Study Timeline

• Study Start: 2015-07-01
• Primary Completion: 2016-11-30
• Study Completion: 2016-11-30
• Status Verified: 2017-08
• Study First Submitted: 2017-08-18
• Study First Submitted QC: 2017-08-25
• Last Update Submitted: 2017-08-25
• Study First Posted: 2017-08-29
• Last Update Posted: 2017-08-29

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 60

Inclusion Criteria

• Healthy volunteers
• Right-handed

Exclusion Criteria

• Current or past psychiatric disease
• Current or past physical illness
• Psychoactive medication
• Tobacco smokers
• MRI contraindications (e.g. metal in body, claustrophobia)
• Anosmia
• Medication known to interfere with olfactory processing

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Placebo	Placebo	sodium chloride solution, intranasal application 30 min prior to the experiment
Oxytocin	Oxytocin	40 IU Oxytocin, intranasal application 30 min prior to the experiment

Primary Outcome Measures

Name	Time	Method
Forced-choice ratings of morphed emotional faces with varying intensities (neutral to fearful).	30 min after nasal spray administration	After each trial, subjects were asked to use a button response grip to indicate whether they perceived the depicted face as neutral or fearful.
Response time for facial stimuli ratings.	30 min after nasal spray administration
Blood-oxygen-level dependent signal in response to chemosensory cues.	30 minutes after nasal spray administration	The modulatory effect of oxytocin on neural correlates Using functional magnetic resonance imaging, signal changes in the amygdala, hippocampus and the anterior cingulate cortex in response to olfactory cues of stress and sport (axillary sweat obtained from an unrelated sample of 30 healthy men undergoing the Trier Social Stress Test and ergometer training as control).

Secondary Outcome Measures

Name	Time	Method
Saliva oxytocin concentrations	immediately before the nasal spray administration and (on average) 10 minutes after the fMRI experiment
Questionnaire measurement of mood (PANAS).	15 minutes before the nasal spray administration and (on average) 10 minutes after the fMRI experiment
Questionnaire measurement of anxiety (STAI).	15 minutes after nasal spray administration and (on average) 10 minutes after the fMRI experiment