Contribution of L-Tyrosine to Human Decision Making in Stressful Situations

Stress, Psychological Clinical Trial

— TYRO-STRESS  

Official title:

Contribution of L-Tyrosine to Human Decision Making in Stressful Situations

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04518254
• Other study ID #: 2018PPRC25
• Secondary ID: 2019-A03194-53
• Status: Completed
• Phase: N/A
• Start date: November 18, 2021
• Est. completion date: April 7, 2022

Study information

• Verified date: November 2022
• Source: Direction Centrale du Service de Santé des Armées
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 17
• Est. completion date: April 7, 2022
• Est. primary completion date: April 7, 2022
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 65 Years

Eligibility

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

Related Conditions & MeSH terms

• Stress, Psychological

Intervention

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
• Placebo
The participants will be administered 4 capsules of Lactose 500 mg (placebo) per oral route

Behavioral:
• Cognitive tasks
The participants will perform cognitive decision-making tasks: Simon task and masking task after treatment administration

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

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.
• Electroencephalography (EEG)
Electroencephalography measurements will be performed during cognitive tasks.

Locations

Country	Name	City	State
France	Institut de Recherche Biomédicale des Armées	Brétigny-sur-Orge

Sponsors (1)

Lead Sponsor	Collaborator
Direction Centrale du Service de Santé des Armées

Country where clinical trial is conducted

France, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Reaction Time	Reaction Time at the cognitive tasks	At day 9 (9 days after enrollment)
Primary	Number of incorrect responses	Number of incorrect responses at the cognitive tasks	At day 9
Secondary	Error negativity	Error negativity on motor evoked potentials (measured by EMG)	At day 9
Secondary	Correlation coefficient between anxiety level and tyrosinemia	Correlation coefficient between anxiety level (measured by anxiety scale) and tyrosinemia (measured in blood sample)	At day 9
Secondary	Correlation coefficient between anxiety level and plasma tyrosine	Correlation coefficient between anxiety level (measured by anxiety scale) and plasma tyrosine (measured in blood sample)	At day 9
Secondary	Correlation coefficient between cortisolaemia and melatoninaemia	Correlation coefficient between cortisolaemia and melatoninaemia (measured in blood sample)	At day 9