Oxytocin and Dopamine's Effect on Vicarious Optimism

NCT ID: NCT03891095

Last Updated: 2019-03-26

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 156 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2018-12-01
• Study Completion Date: 2019-01-16

Brief Summary

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

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).

Conditions

Oxytocin Group; L-DOPA Group; Placebo Group

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: TRIPLE

Study Groups

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)

Group Type: EXPERIMENTAL

Oxytocin

Intervention Type: DRUG

intranasally administrated

Placebos

Intervention Type: DRUG

intranasally administrated and orally administered

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)

Group Type: EXPERIMENTAL

L-DOPA

Intervention Type: DRUG

orally administered

Placebos

Intervention Type: DRUG

intranasally administrated and orally administered

Placebo

Participants in the Placebo group received spray and oral placebos. 24 IU saline (spray placebo) 187.5 mg calcium carbonate (oral placebo)

Group Type: PLACEBO_COMPARATOR

Placebos

Intervention Type: DRUG

intranasally administrated and orally administered

Interventions

Oxytocin

intranasally administrated

Intervention Type: DRUG

L-DOPA

orally administered

Intervention Type: DRUG

Placebos

intranasally administrated and orally administered

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

• healthy subjects without past or current psychiatric or neurological disorders

Exclusion Criteria

• subjects with past or current psychiatric or neurological disorders

• Eligible Sex: MALE
• Accepts Healthy Volunteers: Yes

Sponsors

Yale University

OTHER

Sponsor Role: collaborator

Beijing Normal University

OTHER

Sponsor Role: lead

Responsible Party

ma, yina

Principal Investigator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Beijing Normal University

Beijing, Beijing Municipality, China

Countries

China

Other Identifiers

OT-DA-Vicarious optimism

Identifier Type: -

Identifier Source: org_study_id