Neurobiological Bases of Paternal Nurturance

What Was Tested

The trial (not phased) is built around Oxytocin and Vasopressin.

The overall goal of this project is to identify the genetic, hormonal, and neurobiological influences on paternal nurturing behavior and to determine if fathers' neural responses to infants can be modulated by neuropeptides known to play a role in parenting in experimental animal models.

It had two arms (groups): OT + placebo (experimental) and AVP + placebo (experimental).

The registry classes the interventions as drug.

More on the Plan

All fathers will receive two fMRI scans on two different occasions, separated by 2-10 days. 15 fathers will be randomized to intranasal OT, the other 15 will be randomized to intranasal AVP.

Within each drug group, the order of administration of drug and placebo will counterbalanced across subjects, such that 15 will receive OT/AVP first, and 15 will receive OT/AVP second.

Afterwards, while still in the scanner, they will listen to infant cry and control stimuli.

After exiting the scanner, fathers will again listen to the cry stimuli and will rate their emotional reaction to the cry stimuli on the following dimensions using a 7 point likert scale: irritated, sympathetic, alarmed, angry, upset, compassionate, distressed, annoyed, and tender.

Who Took Part

Enrollment: 35 actual participants took part.

It was open to people of any sex aged from 18 years with no upper age limit.

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

Examples of who could join: Normal or corrected-to-normal vision of 20/40.

The full record lists 3 inclusion and 9 exclusion criteria; among the exclusions: current or past history of mental illness; active medical or neurological disorder; current or past history of alcohol or drug dependence.

How the Study Was Run

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

Random assignment meant chance, not the researchers, decided who got Oxytocin and who got the comparison, which limits bias.

Each person switched between Oxytocin and the comparison at some point, usually with a gap in between.

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

Those kept unaware of assignments: participant, care provider and investigator.

It started in 2014-08 with completion listed for 2016-02.

It ran at 2 sites in United States (2).

Its stated primary purpose is basic science.

What Was Measured

The main thing measured (primary outcome): Mean Percent Signal Change in Ventral Tegmental Area (VTA) (time frame: Baseline, Visit 2 (Up to 10 days)). Mean Percent Signal Change in Right Ventral Striatum (time frame: Baseline, Visit 2 (Up to 10 days)). Mean Percent Signal Change in Right Medial Orbitofrontal Cortex (time frame: Baseline, Visit 2 (Up to 10 days)).

It also tracked 6 secondary outcomes, for example Change in Plasma Levels of Vasopressin (AVP), Change in Plasma Levels of Oxytocin (OT), Difference in Cry Rating Scores Between OT and Placebo, Difference in Cry Rating Scores Between AVP and Placebo, Mean Percent Signal Change in Primary Auditory Cortex and Mean Percent Signal Change in Right Lateral Septum.

What This Means in Plain Language

Put simply, this is a not phased, randomized trial of Oxytocin and Vasopressin in 35 people.

Its size is small, so on its own it can only give an early look.

The trial is marked completed; results are posted on the registry, and this page does not restate them.

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