Contribution of L-Tyrosine to Human Decision Making in Stressful Situations (TYRO-STRESS)

November 23, 2022 updated by: Direction Centrale du Service de Santé des Armées
L-tyrosine is a chemical precursor of dopamine. Under specific conditions, tyrosine administration can increase brain dopamine levels and therefore several studies have explored whether tyrosine supplementation can have a beneficial effect on cognitive and behavioural performance that is dependent on dopaminergic function. However, the effects of tyrosine supplementation are mixed: some studies show positive effects while others do not. Stress leads to an increase in dopaminergic activity and turnover in the brain, resulting in a decrease in brain dopamine levels. We propose to study the contribution of tyrosine to decision making and more particularly to the processes of response selection (mediated by the prefrontal cortex and under the influence of the dopaminergic system) in stressful situations.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
17

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • France
      • Brétigny-sur-Orge, France, 91223
        • Institut de Recherche Biomédicale des Armées

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

14 years to 61 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • From 18 to 65 years of age

Exclusion Criteria:

  • Tyrosine intake within the previous 15 days
  • History of neurological or psychiatric disorder
  • History of nephrological or endocrine disorder or liver failure
  • Hereditary tyrosinemia

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Tyrosine - Test
4 similar visits (day 0, day 3, day 6, day 9): Administration of L-tyrosine No stress exposure
Biological: Blood collection
A blood sample will be collected before and after treatment administration
Drug: L-Tyrosine 500 Mg
The participants will be administered 4 capsules of L-Tyrosine 500 mg per oral route
Behavioral: Cognitive tasks
The participants will perform cognitive decision-making tasks: Simon task and masking task after treatment administration
Behavioral: Anxiety scale
Spielberger's State Trait Anxiety Inventory (STAI) will be filled by the participants before and after cognitive tasks
Device: Electromyography (EMG)
Electromyography measurements will be performed during cognitive tasks.
Device: Electroencephalography (EEG)
Electroencephalography measurements will be performed during cognitive tasks.
Experimental: Tyrosine - Stress
4 similar visits (day 0, day 3, day 6, day 9): Administration of L-tyrosine Stress exposure
Biological: Blood collection
A blood sample will be collected before and after treatment administration
Drug: L-Tyrosine 500 Mg
The participants will be administered 4 capsules of L-Tyrosine 500 mg per oral route
Behavioral: Cognitive tasks
The participants will perform cognitive decision-making tasks: Simon task and masking task after treatment administration
Behavioral: Anxiety scale
Spielberger's State Trait Anxiety Inventory (STAI) will be filled by the participants before and after cognitive tasks
Device: Electromyography (EMG)
Electromyography measurements will be performed during cognitive tasks.
Device: Electroencephalography (EEG)
Electroencephalography measurements will be performed during cognitive tasks.
Other: Stress exposure
Unpleasant but not painful skin stimulations will be administered to the participants at variable intervals on the left leg during the cognitive tasks
Experimental: Placebo - Test
4 similar visits (day 0, day 3, day 6, day 9): Administration of Placebo No stress exposure
Biological: Blood collection
A blood sample will be collected before and after treatment administration
Behavioral: Cognitive tasks
The participants will perform cognitive decision-making tasks: Simon task and masking task after treatment administration
Behavioral: Anxiety scale
Spielberger's State Trait Anxiety Inventory (STAI) will be filled by the participants before and after cognitive tasks
Device: Electromyography (EMG)
Electromyography measurements will be performed during cognitive tasks.
Device: Electroencephalography (EEG)
Electroencephalography measurements will be performed during cognitive tasks.
Drug: Placebo
The participants will be administered 4 capsules of Lactose 500 mg (placebo) per oral route
Experimental: Placebo - Stress
4 similar visits (day 0, day 3, day 6, day 9): Administration of Placebo Stress exposure
Biological: Blood collection
A blood sample will be collected before and after treatment administration
Behavioral: Cognitive tasks
The participants will perform cognitive decision-making tasks: Simon task and masking task after treatment administration
Behavioral: Anxiety scale
Spielberger's State Trait Anxiety Inventory (STAI) will be filled by the participants before and after cognitive tasks
Device: Electromyography (EMG)
Electromyography measurements will be performed during cognitive tasks.
Device: Electroencephalography (EEG)
Electroencephalography measurements will be performed during cognitive tasks.
Other: Stress exposure
Unpleasant but not painful skin stimulations will be administered to the participants at variable intervals on the left leg during the cognitive tasks
Drug: Placebo
The participants will be administered 4 capsules of Lactose 500 mg (placebo) per oral route

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Reaction Time
Time Frame: At day 9 (9 days after enrollment)
Reaction Time at the cognitive tasks
At day 9 (9 days after enrollment)
Number of incorrect responses
Time Frame: At day 9
Number of incorrect responses at the cognitive tasks
At day 9

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Error negativity
Time Frame: At day 9
Error negativity on motor evoked potentials (measured by EMG)
At day 9
Correlation coefficient between anxiety level and tyrosinemia
Time Frame: At day 9
Correlation coefficient between anxiety level (measured by anxiety scale) and tyrosinemia (measured in blood sample)
At day 9
Correlation coefficient between anxiety level and plasma tyrosine
Time Frame: At day 9
Correlation coefficient between anxiety level (measured by anxiety scale) and plasma tyrosine (measured in blood sample)
At day 9
Correlation coefficient between cortisolaemia and melatoninaemia
Time Frame: At day 9
Correlation coefficient between cortisolaemia and melatoninaemia (measured in blood sample)
At day 9

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Direction Centrale du Service de Santé des Armées

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 18, 2021

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 7, 2022

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
April 7, 2022

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 15, 2020

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 15, 2020

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 19, 2020

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 25, 2022

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 23, 2022

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
November 1, 2022

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2018PPRC25
  • 2019-A03194-53 (Other Identifier: IDRCB)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

Undecided

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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