Vasopressin and Pain Perception in the Brain
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|ClinicalTrials.gov Identifier: NCT03446456|
Recruitment Status : Not yet recruiting
First Posted : February 26, 2018
Last Update Posted : April 23, 2018
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.
|Condition or disease||Intervention/treatment||Phase|
|ADH Arginine Vasopressin Antidiuretic Hormone Placebo Analgesia Social Behavior||Drug: Arginine vasopressin Other: Saline||Phase 1 Phase 2|
Show Detailed Description
|Study Type :||Interventional (Clinical Trial)|
|Estimated Enrollment :||122 participants|
|Intervention Model:||Parallel Assignment|
|Intervention Model Description:||This experiment has a between-subjects design. Participants will be randomized into two groups: AVP and control. Both the experimenter and participant will be blinded to the group allocation. Participants have 50%/50% chance of being placed in either group. Participants in the AVP group will receive intranasal AVP and the participants in the control group will receive intranasal saline before the fMRI experiment. The experiment in the fMRI scanner is divided into two phases: an observational phase in which participants will observe a video of a demonstrator experiencing analgesia and a testing phase in which study participants will receive heat pain to investigate how their pain perception. During both phases there will be a placebo condition (pain with the expectation of having received a treatment) and a control condition (pain without the expectation of having received a treatment). All participants will complete both phases, including the observational and testing phase.|
|Masking:||Double (Participant, Investigator)|
|Masking Description:||Randomization will be performed/maintained by the University of Maryland Medical Center Pharmacy. Blind will only be broken in case of a potential medical emergency during the experiment.|
|Primary Purpose:||Basic Science|
|Official Title:||The Influence of Vasopressin on Observational Learning of Placebo Analgesia|
|Estimated Study Start Date :||August 15, 2018|
|Estimated Primary Completion Date :||August 15, 2019|
|Estimated Study Completion Date :||August 15, 2019|
Placebo Comparator: Saline
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.
Intranasal saline will serve as a placebo for participants in the Saline Arm
Other Name: Placebo
Experimental: Arginine vasopressin
Under direction of a research team member, participants will self-administer intranasal vasopressin shortly before beginning the fMRI experiment. The of AVP will be 40IU. The quantity per unit (1 mL) of Arg8-vasopressin synthetic, manufactured by Polypeptide Group Inc. (http://www.polypeptide.com) was 0.323 mg. This amount was diluted in 0.9% sodium chloride (B. Broun Medical Inc.).
A random allocation sequence will be independently generated by the UM Pharmacy. The Principal investigator will call for each experiment. Participants will be first stratified for sex and then randomized to saline (0.4 mL) or vasopressin (40 IU) group, respectively.
Drug: Arginine vasopressin
Intranasal vasopressin will be administered shortly before the fMRI experiment.
Other Name: Arg8-vasopressin synthetic
- Neural outcome [ Time Frame: Day 2 ]Blood oxygenation level dependent (BOLD) responses will allow the identification of relative activation/deactivation in the brain as result of events (e.g. painful stimulations) that will be given during the experiment.
- Pain ratings [ Time Frame: Days 1 (calibration) and 2 (test) ]Participants will provide their pain on a Visual Analogue Scale raging from 0=no pain to 100= maximum unbearable pain. Normal value will be absence of pain.
- Implicit association test (IAT) [ Time Frame: Day 1 ]Implicit racial bias measure
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03446456
|Contact: Research Coordinatorfirstname.lastname@example.org|
|Contact: Nathaniel Haycock, MSemail@example.com|
|Principal Investigator:||Luana Colloca, MD/PHD/MS||University of Maryland Baltimore School of Nursing|