Molecular Basis of Loss Aversion

Study Overview
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Brief Summary
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The goal of this clinical trial is to test the roles of dopamine and norepinephrine in decision making related to loss aversion in the healthy population. The main question it aims to answer is whether temporarily boosting dopamine activity or temporarily suppressing norepinephrine activity has an impact on processing of potential gains and losses in financial decision making, social decision making, transaction decision making and moral decision making. Accordingly, participants will complete four decision-making tasks, namely investment task, driving task, trading task, and die task, after taking madopar, propranolol or placebo. Participants' psychological traits and psychiatric symptoms will be assessed once they are enrolled before the first-session day.

Official Title
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Molecular Basis of Loss Aversion

Conditions
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Healthy

Intervention / Treatment
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* Drug: single-dose madopar, single-dose propranolol, and single-dose placebo by order
* Drug: single-dose madopar, single-dose placebo, and single-dose propranolol by order
* Drug: single-dose propranolol, single-dose madopar, and single-dose placebo by order
* Drug: single-dose propranolol, single-dose placebo, and single-dose madopar by order
* Drug: single-dose placebo, single-dose propranolol, and single-dose madopar by order
* Drug: single-dose placebo, single-dose madopar, and single-dose propranolol by order


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 25-40 years old (including boundary value). Elementary school education or above, able to understand the research content. Body temperature, blood pressure, heart rate, respiratory rate, and electrocardiogram are all normal. Among them, the blood pressure range is 100-139/70-89 mmHg, and the heart rate range is 60-85 beats/min. Exclusion Criteria: Vulnerable groups, including people with mental illness, cognitive impairment, critically ill subjects, minors, pregnant women, illiterates, etc. Family history of genetic diseases. Major physical diseases, including cardiovascular, respiratory, digestive, renal, endocrine, blood and other systemic diseases. History of alcohol/drug dependence. Lactating women. The cardiopulmonary function test results are poor. Have ever taken madopar or propranolol for medical use.

Ages Eligible for Study
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Minimum Age: 25 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: madopar-propranolol-placebo<br>In a within-subjects design, participants will take madopar, propranolol, and placebo each once in three separate sessions. | Drug: single-dose madopar, single-dose propranolol, and single-dose placebo by order<br>* Participants will take madopar, propranolol, and placebo (orange juice) each once in three separate sessions. The interval between every two sessions will be at least 3 days.<br>|
| Other: madopar-placebo-propranolol<br>In a within-subjects design, participants will take madopar, placebo, and propranolol each once in three separate sessions. | Drug: single-dose madopar, single-dose placebo, and single-dose propranolol by order<br>* Participants will take madopar, placebo(orange juice), and propranolol each once in three separate sessions. The interval between every two sessions will be at least 3 days.<br>|
| Other: propranolol-madopar-placebo<br>In a within-subjects design, participants will take propranolol, madopar, and placebo each once in three separate sessions. | Drug: single-dose propranolol, single-dose madopar, and single-dose placebo by order<br>* Participants will take propranolol, madopar, and placebo(orange juice) each once in three separate sessions. The interval between every two sessions will be at least 3 days.<br>|
| Other: propranolol-placebo-madopar<br>In a within-subjects design, participants will take propranolol, placebo, and madopar each once in three separate sessions. | Drug: single-dose propranolol, single-dose placebo, and single-dose madopar by order<br>* Participants will take propranolol, placebo(orange juice), and madopar each once in three separate sessions. The interval between every two sessions will be at least 3 days.<br>|
| Other: placebo-propranolol-madopar<br>In a within-subjects design, participants will take placebo, propranolol, and madopar each once in three separate sessions. | Drug: single-dose placebo, single-dose propranolol, and single-dose madopar by order<br>* Participants will take placebo(orange juice), propranolol, and madopar each once in three separate sessions. The interval between every two sessions will be at least 3 days.<br>|
| Other: placebo-madopar-propranolol<br>In a within-subjects design, participants will take placebo, madopar, and propranolol each once in three separate sessions. | Drug: single-dose placebo, single-dose madopar, and single-dose propranolol by order<br>* Participants will take placebo(orange juice), madopar, and propranolol each once in three separate sessions. The interval between every two sessions will be at least 3 days.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Choices to invest or not in the investment task | Participants decide whether or not to accept investment options that entail a 50/50 chance of winning some amount of money and losing some amount of money. | between 1-2 hours after taking the drugs or the placebo | 
| Response times to invest or not in the investment task | Participants decide whether or not to accept investment options that entail a 50/50 chance of winning some amount of money and losing some amount of money. | between 1-2 hours after taking the drugs or the placebo | 
| Choices to turn or not in the driving task | Participants decide whether or not to make turns during driving in order to sacrifice some number of person(s) to save some number of person(s) . | between 1-2 hours after taking the drugs or the placebo | 
| Response times to turn or not in the driving task | Participants decide whether or not to make turns during driving in order to sacrifice some number of person(s) to save some number of person(s) . | between 1-2 hours after taking the drugs or the placebo | 
| Choices to buy or sell in the trading task | Participants decide whether or not to buy or sell a product at certain prices. | between 1-2 hours after taking the drugs or the placebo | 
| Response times to buy or sell in the trading task | Participants decide whether or not to buy or sell a product at certain prices. | between 1-2 hours after taking the drugs or the placebo | 
| Reported outcomes in die task | Participants report the outcome for each throw of the die. | between 1-2 hours after taking the drugs or the placebo | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Affects | Participants' affects will be assessed using the Positive and Negative Affective Scale (PANAS).Scores can range from 10 to 50 for both the Positive and Negative Affect, with the lower scores representing lower levels of Positive/Negative Affect and higher scores representing higher levels of Positive/Negative Affect. | before and 1 hour after taking the drugs or the placebo |