Oxytocin and Dopamine's Effect on Vicarious Optimism

What Was Tested

In this not phased trial, researchers set out to test Oxytocin.

To investigate the effect of intranasal Oxytocin and L-DOPA's effect on vicarious optimism.

It had three arms (groups): Intranasal oxytocin (experimental), L-DOPA (experimental) and Placebo (placebo comparator).

The registry classes the interventions as drug.

More on the Plan

The current study adopted a double-blind, double-dummy, placebo-controlled mixed design, with Treatment (oxytocin, dopamine, and placebo) as a between-subjects factor, and Target (self, friend, and an identifiable stranger) and Feedback (desirable vs. undesirable) as within-subjects factors.

Upon arrival, participants first completed a set of questionnaires, including mood measurements and other questionnaires related to optimistic or prosocial tendency.

At the end, participants completed the mood measurement again, as well the debriefing questionnaires which designed to measure their beliefs about the experimental process.

Participants completed two estimation sessions for one target before beginning with the next target, and the order of targets was counterbalanced across participants within each group.

Who Took Part

The registry lists 156 actual participants took part.

It was open to men only.

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

Examples of who could join: Healthy subjects without past or current psychiatric or neurological disorders.

The full record lists 1 inclusion and 1 exclusion criteria; among the exclusions: subjects with past or current psychiatric or neurological disorders.

How the Study Was Run

The set-up was randomized, crossover and triple-blind.

Because people in this Oxytocin study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

In the crossover set-up each of the participants took both Oxytocin and the comparison in turn, acting as their own control.

Blinding on both sides kept the participants and researchers unaware of who received Oxytocin.

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

It started in 2018-12-01 with completion listed for 2019-01-15.

It ran at 1 site in China.

Its stated primary purpose is basic science.

What Was Measured

Researchers chose this as the main measure: Belief update value for self, friend and stranger (time frame: 40~70 minutes after drug administration).

What This Means in Plain Language

Put simply, this is a not phased, randomized trial of Oxytocin in 156 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.