NCT03446456 · University of Maryland, Baltimore
Vasopressin and Pain Perception in the Brain
What this study is about
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.
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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. Research has shown that patients' expectation that a treatment will reduce pain influences individual perception of pain, even if the treatment has no active ingredient. The expectancy-induced analgesia emerges due to a modulation of the individual pain experience of patients by an engagement of endogenous inhibitory systems in the central nervous system. The development of expectancy-induced analgesia can be generated in several ways. The investigators have previously demonstrated that social information and observational learning (e.g. the patient observes analgesia in another person receiving a treatment) can lead to expectancy-induced analgesia and pain reduction. However, the neural mechanisms (mechanisms in the brain) of how these expectancies are acquired and the neural mechanisms of analgesia induced by observational learning are unknown. The investigators recently established a procedure to investigate neural mechanisms of observational learning in placebo analgesia. Here the investigators propose to investigate the influence of vasopressin, a neurotransmitter that is important for social interaction, on observational learning. The investigators will use functional magnetic resonance imaging (fMRI), a non-invasive method, to investigate neural activity in humans. Participants will either receive vasopressin or saline with a nasal spray. During fMRI scanning, participants will then undergo an observational learning phase, where the study participants will learn the experience of analgesia in another person through a video, and a testing phase, where participants will perceive painful stimulations with the same cues as the observational phase. The comparison of the vasopressin group and the saline group will allow us to investigate how vasopressin influences behavioral effects of observational learning on pain perception as well as its effect on the neural processing of observational learning. A better understanding of how the human brain processes observationally-induced analgesia would allow us to improve the therapeutic context of pain treatments by increasing the contextual factors which help patients cope with pain.
Interventions
DRUG
Arginine vasopressin
Intranasal vasopressin will be administered shortly before the fMRI experiment.
OTHER
Saline
Intranasal saline will serve as a placebo for participants in the Saline Arm
BEHAVIORAL
Observational learning
During the observational learning intervention, participants will learn the experience of analgesia in another person via a video. Participants will learn the analgesia nature of the placebo cream and the neutral nature of the control cream.
OTHER
fMRI data aquisition
All participants from the intranasal vasopressin and intranasal saline groups will go through a fMRI data acquisition to obtain the brain structural, brain resting-states and functional MRI scans.
Primary outcome measures
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
Blood oxygenation level dependent (BOLD) responses will allow the identification of relative activation/deactivation in the brain as a result of events (e.g. painful stimulations) that will be given during the experiment. Changes in the Percentage of BOLD signal are calculated as the BOLD signal in the right supplementary motor area during the 20-second heat pain divided by the whole-brain average BOLD signal during that 20-second heat pain.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Age ( 18-55 years old)
- English speaker (written and spoken)
Exclusion criteria
- 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.
- Family (first degree) history of mania, schizophrenia, or other psychoses
- Lifetime alcohol/drug dependence or alcohol/drug abuse in past 3 months
- Pregnancy or breast feeding
- Color-blindness
- Impaired, uncorrected hearing
- History of angioedema
- High blood pressure (above 140 mmHg) or symptomatic low blood pressure
- History of fainting
- Left handed
- Allergies or sensitivities to creams, lotions or food coloring
- Any non-organic implant or any non-removable metal device (e.g. pacemaker, cochlear implants, stents, surgical clips, non-removable piercings)
- Any prior eye injury or the potential of a foreign body in the eye (e.g. worked in metal fields)Persisting functional impairment due to a head trauma
- Fear of closed spaces
- Any other contraindications for MRI (e.g. large tattoos on head and neck)
- Previously participated in a "Pain Perception in the Brain" Study
- Failed drug test (testing for opiates, cocaine, methamphetamines, amphetamines and THC)
Where
- Baltimore, Maryland
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Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 9, 2026 · Source of record for eligibility and locations