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

What Was Tested

In this phase 1 trial, researchers set out to test Oxytocin.

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.

It had two arms (groups): Oxytocin (experimental) and Placebo (placebo comparator).

The registry classes the interventions as drug.

More on the Plan

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.

Who Took Part

80 actual participants took part.

It was open to men only aged from 18 years up to 60 years.

Healthy volunteers could join, not only people with the condition.

Examples of who could join: Healthy male volunteers.

The full record lists 1 inclusion and 4 exclusion criteria; among the exclusions: current or past psychiatric disease; current or past physical illness; psychoactive medication.

How the Study Was Run

Design: randomized, parallel-group and triple-blind.

The participants were allocated by chance, so the Oxytocin group and the comparison group should start out alike.

The Oxytocin group and the comparison group ran side by side rather than switching.

As a double-blind Oxytocin study, the assignments were hidden from both participants and investigators until the end.

Those kept unaware of assignments: participant, investigator and outcomes assessor.

It started in 2011-08 with completion listed for 2012-05.

It ran at 1 site in Germany.

Its stated primary purpose is basic science.

What Was Measured

Researchers chose this as the main measure: baseline startle magnitude and affective modulation of the startle magnitude after oxytocin and placebo administration (time frame: 24 Months).

It also tracked 2 secondary outcomes, for example moral decision making after oxytocin and placebo administration and oxytocin receptor (OXTR) polymorphism and correlation with social behavior.

What This Means in Plain Language

Put simply, this is a phase 1, randomized trial of Oxytocin in 80 people.

The trial is marked completed; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the Oxytocin compound page, all human trials.