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

NCT04518254 | Completed

• 2 other identifiers: 2018PPRC252019-A03194-53
• Study Type: interventional
• Target: 17
• Locations: 1 country
• Sites: 1

Brief 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.

Conditions

Stress, Psychological

Keywords

L-tyrosine

Outcome Measures

Primary Outcomes (2)

• Reaction Time

  Reaction Time at the cognitive tasks

  At day 9 (9 days after enrollment)

• Number of incorrect responses

  Number of incorrect responses at the cognitive tasks

  At day 9

Secondary Outcomes (4)

• Error negativity

  At day 9

• Correlation coefficient between anxiety level and tyrosinemia

  At day 9

• Correlation coefficient between anxiety level and plasma tyrosine

  At day 9

• Correlation coefficient between cortisolaemia and melatoninaemia

  At day 9

Study Arms (4)

Tyrosine - Test

EXPERIMENTAL

4 similar visits (day 0, day 3, day 6, day 9): Administration of L-tyrosine No stress exposure

Biological: Blood collection; Drug: L-Tyrosine 500 Mg; Behavioral: Cognitive tasks; Behavioral: Anxiety scale; Device: Electromyography (EMG); Device: Electroencephalography (EEG)

Tyrosine - Stress

EXPERIMENTAL

4 similar visits (day 0, day 3, day 6, day 9): Administration of L-tyrosine Stress exposure

Biological: Blood collection; Drug: L-Tyrosine 500 Mg; Behavioral: Cognitive tasks; Other: Stress exposure; Behavioral: Anxiety scale; Device: Electromyography (EMG); Device: Electroencephalography (EEG)

Placebo - Test

EXPERIMENTAL

4 similar visits (day 0, day 3, day 6, day 9): Administration of Placebo No stress exposure

Biological: Blood collection; Drug: Placebo; Behavioral: Cognitive tasks; Behavioral: Anxiety scale; Device: Electromyography (EMG); Device: Electroencephalography (EEG)

Placebo - Stress

EXPERIMENTAL

4 similar visits (day 0, day 3, day 6, day 9): Administration of Placebo Stress exposure

Biological: Blood collection; Drug: Placebo; Behavioral: Cognitive tasks; Other: Stress exposure; Behavioral: Anxiety scale; Device: Electromyography (EMG); Device: Electroencephalography (EEG)

Interventions

Blood collection BIOLOGICAL

A blood sample will be collected before and after treatment administration

Placebo - Stress; Placebo - Test; Tyrosine - Stress; Tyrosine - Test

L-Tyrosine 500 Mg DRUG

The participants will be administered 4 capsules of L-Tyrosine 500 mg per oral route

Tyrosine - Stress; Tyrosine - Test

Placebo DRUG

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

Placebo - Stress; Placebo - Test

Cognitive tasks BEHAVIORAL

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

Placebo - Stress; Placebo - Test; Tyrosine - Stress; Tyrosine - Test

Stress exposure OTHER

Unpleasant but not painful skin stimulations will be administered to the participants at variable intervals on the left leg during the cognitive tasks

Placebo - Stress; Tyrosine - Stress

Anxiety scale BEHAVIORAL

Spielberger's State Trait Anxiety Inventory (STAI) will be filled by the participants before and after cognitive tasks

Placebo - Stress; Placebo - Test; Tyrosine - Stress; Tyrosine - Test

Electromyography (EMG) DEVICE

Electromyography measurements will be performed during cognitive tasks.

Placebo - Stress; Placebo - Test; Tyrosine - Stress; Tyrosine - Test

Electroencephalography (EEG) DEVICE

Electroencephalography measurements will be performed during cognitive tasks.

Placebo - Stress; Placebo - Test; Tyrosine - Stress; Tyrosine - Test

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• From 18 to 65 years of age

You may not qualify if:

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

Sponsors & Collaborators

• Direction Centrale du Service de Santé des Armées: lead

Study Sites (1)

Institut de Recherche Biomédicale des Armées

Brétigny-sur-Orge, 91223, France

Location

MeSH Terms

Conditions

Stress, Psychological

Interventions

Blood Specimen Collection; Tyrosine; Electromyography; Electroencephalography

Condition Hierarchy (Ancestors)

Behavioral Symptoms; Behavior

Intervention Hierarchy (Ancestors)

Specimen Handling; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Punctures; Surgical Procedures, Operative; Investigative Techniques; Amino Acids, Aromatic; Amino Acids, Cyclic; Amino Acids; Amino Acids, Peptides, and Proteins; Electrodiagnosis; Myography; Diagnostic Techniques, Neurological

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: The pharmacist, carrying out the packaging and labelling of the treatment units, will ensure the blinding. Neither the participant nor the investigator will know what treatment is being administered.
• Purpose: PREVENTION
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: The study is composed of 4 arms: 1. Tyrosine treatment without stress exposure 2. Tyrosine treatment with stress exposure 3. Placebo treatment without stress exposure 4. Placebo treatment with stress exposure Every participants will participate in the 4 arms in a random order.

Study Record Dates

• First Submitted: August 15, 2020
• First Posted: August 19, 2020
• Study Start: November 18, 2021
• Primary Completion: April 7, 2022
• Study Completion: April 7, 2022
• Last Updated: November 25, 2022

Record last verified: 2022-11

Locations

FR (1)