Vasopressin and Pain Perception in the Brain

What Was Tested

The trial (phase 1, phase 2) is built around Vasopressin.

The feeling of pain is not just a sensory experience, but is also influenced by emotions, beliefs and expectations, making pain a highly subjective experience.

This is evident in clinical practice, where the behavior of the physician and the treatment context can strongly influence the pain experience of patients.

It had two arms (groups): Saline (placebo comparator) and Arginine vasopressin (experimental).

Under direction of a research team member, participants will self-administer intranasal normal saline shortly before beginning the fMRI experiment. Investigators, staff, and participants were blinded to the treatment options. Each of the agents will be administrated by means of a nasal spray. Participants will be instructed by a nurse/PI to self-administer the nasal spray as follows: one spray in each nostril alternating sides, 30 seconds apart for a total of two sprays per nostril.

The registry classes the interventions as behavioral, drug and other.

More on the Plan

More specifically, the investigators will determine how observing another person experiencing analgesia shapes subsequent behavioral and neural responses to painful stimulations.

Hypothesis 1: The investigators expect that AVP will boost activation in brain regions involved in social cognition.

This experiment has a between-subject study design.

Participants will be randomized into an AVP group and a control group.

Who Took Part

Enrollment: 56 planned participants were the target.

It was open to people of any sex aged from 18 years up to 65 years.

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

Examples of who could join: Age ( 18-55 years old). English speaker (written and spoken).

The full record lists 2 inclusion and 19 exclusion criteria; among the exclusions: cardiovascular, neurological diseases, pulmonary abnormalities, kidney disease, liver disease, degenerative neuromuscular disease, history of cancer within past 3 years; any history of chronic pain disorder or currently in pain; severe psychiatric condition (e.g. schizophrenia, bipolar disorders, mania, autism) and /or psychiatric condition leading to treatment and/or hospitalization within the last 3 years.

How the Study Was Run

It was run as a randomized, parallel-group and double-blind study.

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

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

Neither the participants nor the staff measuring them knew who was on Vasopressin, so expectations could not easily colour the readings.

Those kept unaware of assignments: participant and investigator.

It started in 2018-09-17 with completion listed for 2026-09-30.

It ran at 1 site in United States.

Its stated primary purpose is basic science.

What Was Measured

Primary outcome: Change in BOLD Singal in Supplementary Motor Area Compared to Whole Brain Average During the Painful Stimulation (time frame: Day 2, the average of 24 trials of painful stimulations with each stimulation lasting 20 seconds).

It also tracked 2 secondary outcomes, for example Heating Temperature and Pain Ratings.

What This Means in Plain Language

Put simply, this is a phase 1, phase 2, randomized trial of Vasopressin in 56 people.

It is still recruiting; results are posted on the registry, and this page does not restate them.

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