Oxytocin Modulation of Startle Reactivity to Social Stimuli and Moral Decision Making

Phase 1

Completed

• Conditions: Healthy Male Volunteers
• Interventions: Drug: Oxytocin

• Registration Number: NCT01607970
• Lead Sponsor: University Hospital, Bonn

Brief Summary

The purpose of this study is to determine whether oxytocin affects the modulation of startle reactivity by aversive social stimuli and to investigate the oxytocin effect on moral judgements. Furthermore the investigators explore the effects of oxytocin receptor (OXTR) polymorphisms on behavioral responses to social stimuli.

Detailed Description

The neuropeptide oxytocin (OXT) can enhance the impact of positive social cues but may reduce that of negative ones, although it is unclear whether the latter causes blunted emotional responses. After OXT or placebo application participants are exposed to acoustic startle probes presented alone and during viewing of 60 color pictures mostly selected from the 'International Affective Picture System'. The paradigm featured 20 negative (mostly threatening), 20 neutral, and 20 positive pictures, presented for 5 s each. In the other part of the experiment, after intranasal OXT or placebo application participants respond to 60 moral dilemmas.

Study Timeline

• Study Start: 2011-08
• Status Verified: 2012-05
• Primary Completion: 2012-05
• Study Completion: 2012-05
• Study First Submitted: 2012-05-23
• Study First Submitted QC: 2012-05-25
• Last Update Submitted: 2012-05-25
• Study First Posted: 2012-05-30
• Last Update Posted: 2012-05-30

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 80

Inclusion Criteria

• Healthy male volunteers

Exclusion Criteria

• Current or past psychiatric disease
• Current or past physical illness
• Psychoactive medication
• Tobacco smokers

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Oxytocin	Oxytocin	24 IU Oxytocin, intranasal application 45 min prior to the experiment
Placebo	Oxytocin	intranasal application, sodium chloride solution, 3 puffs per nostril

Primary Outcome Measures

Name	Time	Method
baseline startle magnitude and affective modulation of the startle magnitude after oxytocin and placebo administration	24 Months	The experimental tasks started 45 min after intranasal OXT/PLC administration. The STARTLE-paradigm features 20 negative (mostly threatening), 20 neutral, and 20 positive pictures, presented for 5 s each. The startle stimulus consists of a single 50-ms burst of white noise (100 dB) with nearly instantaneous rise and was delivered binaurally via headphones during 60% of the pictures (i.e. 12 from each category) at 2 - 4 s after picture onset. We examined the baseline startle magnitude as well as the affective modulation of the startle magnitude.

Secondary Outcome Measures

Name	Time	Method
moral decision making after oxytocin and placebo administration	24 months	The experimental tasks started 45 min after OXT/PLC administration. The moral dilemmas performed in the present study were identical to those published previously by Greene et al.(2001).
oxytocin receptor (OXTR) polymorphism and correlation with social behavior	24 months	OXTR genotyping, social behavior testing

Trial Locations

Locations (1)

Department of Psychiatry, University of Bonn; 🇩🇪 Bonn, Germany