Oxytocin and Dopamine's Effect on Vicarious Optimism

• ClinicalTrials.gov Identifier: NCT03891095
• Recruitment Status: Completed
• First Posted: March 26, 2019
• Last Update Posted: March 26, 2019
• Sponsor: Beijing Normal University
• Collaborator: Yale University
• Information provided by (Responsible Party): ma, yina, Beijing Normal University

Study Description

Brief Summary:

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

Condition or disease	Intervention/treatment	Phase
Oxytocin Group; L-DOPA Group; Placebo Group	Drug: Oxytocin; Drug: L-DOPA; Drug: Placebos	Not Applicable

Detailed Description:

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. Participants then self-administered with the pharmacological challenge 40 min before the main task, i.e., the belief updating task where participants indicated and updated their beliefs about the future of oneself, a gender-matched best friend, and a gender-matched identifiable stranger. At the end, participants completed the mood measurement again, as well the debriefing questionnaires which designed to measure their beliefs about the experimental process.

For the vicarious optimism task, participants completed three blocks of the two-session belief updating task where they were asked to estimate the likelihood of adverse life events happening to three targets: themselves (referred as Self), a gender-matched best friend (referred as Friend), and an identifiable stranger (whose name, brief description and picture were presented to the participants to get familiar with before the estimation, such as "The stranger is Zhexing, a 25-year-old male, Chinese"; referred as Stranger).

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. For the first session of each target block, participants were first presented with 30 different adverse life events (in a random order) and estimated the likelihood of each event happening to the target in the future (the 1st estimation, referred to as E1) on a self-paced basis. Participants were then presented with the probability of each event occurring to an average person in a similar environment (Feedback) for 2s. In the second session, participants estimated the likelihood of the same 30 events (in a random order) happening to the target person again without receiving feedback (the 2nd estimation, referred to as E2).

Study Design

• Study Type: Interventional (Clinical Trial)
• Actual Enrollment: 156 participants
• Allocation: Randomized
• Intervention Model: Crossover Assignment
• Masking: Triple (Participant, Investigator, Outcomes Assessor)
• Primary Purpose: Basic Science
• Official Title: Oxytocin and Dopamine's Effect on Vicarious Optimism
• Actual Study Start Date: December 1, 2018
• Actual Primary Completion Date: January 15, 2019
• Actual Study Completion Date: January 16, 2019

Arms and Interventions

Arm	Intervention/treatment
Experimental: Intranasal oxytocin; Oxytocin (OXT), a neuropeptide produced in the hypothalamus, is a key modulator of complex socioaffective responses including affiliation, social approach and attachment, stress and anxiety. Subjects receiving an intranasal spray of OXT (24 IU or 40.32 mg; Syntocinon-spray; Novartis, Switzerland)	Drug: Oxytocin; intranasally administrated; Drug: Placebos; intranasally administrated and orally administered
Experimental: L-DOPA; L-DOPA, a neuropeptide who is a key modulator of complex socioaffective responses including reward, social decision making, learning. Subjects receiving 187.5 mg Madopar (L-DOPA treatment, including 150 mg L-3,4-dihydroxyphenylalanine, together with 37.5 mg benserazide, which promotes higher levels of dopamine in the brain while minimizing side effects from peripheral dopamine)	Drug: L-DOPA; orally administered; Drug: Placebos; intranasally administrated and orally administered
Placebo Comparator: Placebo; Participants in the Placebo group received spray and oral placebos. 24 IU saline (spray placebo) 187.5 mg calcium carbonate (oral placebo)	Drug: Placebos; intranasally administrated and orally administered

Outcome Measures

Primary Outcome Measures :

1. Belief update value for self, friend and stranger [ Time Frame: 40~70 minutes after drug administration ]
   In the vicarious optimistic bias task, participants would make first estimation about the happening likelihood for each event for themselves, friend, and stranger and then receive feedback about the general likelihood of each event happened in future. After all events first estimation, participants would estimate all the event again. So, for the belief update, we used the second estimation value to minus the first estimation value to get the update value, as well as calculating the update value in desirable condition (first estimation < feedback) and undesirable condition (first estimation < feedback). Then investigated the general belief updating (gBU) and optimistic belief updating (using desirableBU-undesirableBU) for the three target (self vs. friend vs. stranger) in three treatment groups (Oxytocin vs. L-DOPA vs. Placebo)

Eligibility Criteria

• Ages Eligible for Study: Child, Adult, Older Adult
• Sexes Eligible for Study: Male
• Gender Based Eligibility: Yes
• Gender Eligibility Description: we opted to recruit only males for the present study.
• Accepts Healthy Volunteers: Yes

Criteria

Inclusion Criteria:

• healthy subjects without past or current psychiatric or neurological disorders

Exclusion Criteria:

• subjects with past or current psychiatric or neurological disorders

Contacts and Locations

Locations

China, Beijing

Beijing Normal University

Beijing, Beijing, China, 100000

Sponsors and Collaborators

Beijing Normal University

Yale University

More Information

• Responsible Party: ma, yina, Principal Investigator, Beijing Normal University
• ClinicalTrials.gov Identifier: NCT03891095
• Other Study ID Numbers: OT-DA-Vicarious optimism
• First Posted: March 26, 2019
• Last Update Posted: March 26, 2019
• Last Verified: March 2019

• Studies a U.S. FDA-regulated Drug Product: No
• Studies a U.S. FDA-regulated Device Product: No

Keywords provided by ma, yina, Beijing Normal University:

intranasal oxytocin; L-DOPA; Vicarious optimism

Additional relevant MeSH terms:

Oxytocin; Oxytocics; Reproductive Control Agents; Physiological Effects of Drugs