Conditions: Healthy
Keywords: Social cooperation Oxytocin Vasopressin Prisoner's Dilemma game Empathy fMRI
Allocation: RANDOMIZED | Intervention model: FACTORIAL
Enrollment: 707
Healthy volunteers: yes

Brief summary:
The project has three overall objectives. The first is to determine whether and how administration of intranasal oxytocin (OT) and intranasal vasopressin (AVP) influence cooperative decision-making and neural responses to cooperative and un-cooperative social interactions. The second is to determine whether and how intranasal vasopressin influences subjective evaluations of and neural responses to same and opposite-sex face stimuli and to determine if any of these effects persist beyond the period of AVP exposure. The third objective is to determine if intranasal OT influences empathy-related behavior and associated brain activity.

Detailed description:
There are several objective to the study.

Objective 1: In this double-blind, placebo-controlled, pharmaco- fMRI study, men and women will be randomized to treatment with either 24 IU intranasal OT, 20 IU intranasal AVP, or placebo (PL). Approximately 40 minutes later, brain function will be imaged with fMRI as participants play an iterated Prisoner's Dilemma game with same-sex partners. The resulting data will be analyzed to investigate OT and AVP effects on cooperative behavior and the neural response to cooperative social interactions.

In addition to this cross-sectional design, a subset of participants will return on a second day for a within-subject study.

Objective 2: Men and healthy women will be randomized to treatment with either 40 IU intranasal AVP or a saline placebo approximately 30 minutes before their brain function is measured with fMRI as they view same and other-sex faces. All subjects will be scanned a second time several days later with no treatment to evaluate the persistence of AVP effects over time. The resulting data will be analyzed to investigate AVP effects on subjective evaluations and neural responses to viewing same and opposite sex faces.

Objective 3: Healthy men and healthy women will receive either 24IU intranasal OT or PL approximately 40 minutes before their brain function is measured with fMRI as they view animations of geometric shapes depicting either random movement or social interactions such as playing, chasing, fighting. All participants will receive PL on scan 1 and will be randomized to either 24IU intranasal OT or PL on scan 2. The resulting data will be analyzed to investigate OT effects on subjective evaluations and neural responses to the animations.

Arms:
arm 1: The AVP group of healthy volunteers will self-administer vasopressin solution prior to completing the PD task. arm 2: The OT group of healthy volunteers will self-administer oxytocin solution prior to completing the PD task. arm 3: The placebo group of healthy volunteers will self-administer a placebo spray prior to completing the PD task. arm 4: Some healthy volunteer participants who received drug in their first session will receive placebo in their second session and vice-versa prior to completing the PD task. For each gender, half will receive AVP in one session and placebo in the other session, and half will receive OT in one session and placebo in the second session. In each group, half of the subjects will receive drug first and half will receive placebo first. Additionally, a group of subjects who receive placebo the first time will receive placebo the second time. arm 5: Healthy volunteers between the ages of 21-30 years will receive Faces Intranasal Vasopressin (AVP) prior to completing the Faces task during fMRI scanning. arm 6: Healthy volunteers between the ages of 21-30 years will receive placebo prior to completing the Faces task during fMRI scanning. arm 7: Healthy volunteers between the ages of 18-30 years will receive placebo at scan 1 and OT at scan 2 prior to completing an empathy task. arm 8: Healthy volunteers between the ages of 18-30 years will receive placebo at scan 1 and placebo at scan 2 prior to completing an empathy task. arm 9: Depressed or anxious men between the ages of 18 and 22 will receive intranasal OT prior to completing the Prisoner's Dilemma game task and MRI scan. arm 10: Depressed or anxious men between the ages of 18 and 22 will receive intranasal placebo prior to completing the Prisoner's Dilemma game task and MRI scan. arm 11: Healthy normal men between the ages of 18 and 22 will receive lorazepam prior to completing the Prisoner's Dilemma game task and MRI scan.

Interventions: intervention 1: Intranasal Oxytocin (OT) 24 IU intervention 2: Intranasal Vasopressin (AVP) intervention 3: Intranasal Placebo intervention 4: Intranasal Vasopressin (AVP) 40 IU intervention 5: Lorazepam
Intervention descriptions: intervention 1: Participants will self-administer a single dose of 24 international units (IU) oxytocin. Five puffs per nostril, each with 2.4 IU oxytocin. Ten puffs total. intervention 2: Participants will self-administer a 1 ml solution containing 20 units of AVP. Five puffs per nostril, each with 2 International Units (IU) AVP. Ten puffs total). intervention 3: Participants will receive placebo sprays that are pH adjusted to comparable levels of the drugs given. Five puffs per nostril; ten puffs total. intervention 4: Participants will self-administer a 0.5 ml solution containing 40 international units (IU) of AVP. 5 puffs in total, each with 4 International Units (IU) AVP. intervention 5: Subjects will take 1.0 mg of lorazepam orally 60 minutes prior to fMRI scan.

Protocol document: