NCT04518254

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

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 17 (actual)
• Sponsor: Direction Centrale du Service de Santé des Armées · Academic / Other
• Sex: All
• Age: 18 Years – 65 Years
• Healthy volunteers: Accepted

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

Interventions

Type	Name	Description
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
DRUG	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.
DEVICE	Electroencephalography (EEG)	Electroencephalography measurements will be performed during cognitive tasks.

Timeline

• Start date: 2021-11-18
• Primary completion: 2022-04-07
• Completion: 2022-04-07
• First posted: 2020-08-19
• Last updated: 2022-11-25

Locations

1 site across 1 country: France