Mod of Cognitive Flexibility by tDCS, Tyrosine Polymorphisms in the COMT Gene

Sheffield Hallam University

Status: Unknown

Conditions: Modulation of Cognitive Flexibility by Transcranial Direct Current Stimulation, Tyrosine Administration and Polymorphisms in the COMT Gene

Treatments: Combination Product: tdcs (sham/anodal) + drug (placebo/tyrosine)

Study type: Interventional

Funder types: Other

Identifiers

NCT03845920

SheffieldHallamAquili2019

Details and patient eligibility

About

The current study would examine whether increases in endogenous dopaminergic activity via tyrosine and the (presumed) excitation of these by anodal tDCS of the dlPFC could causally be related to cognitive flexibility as measured by task switching and reversal learning.

Additionally, the study will test whether the Val158Met-polymorphism in the catechol- O-methyltransferase (COMT) gene could also predict the effect of TYR supplementation, as this gene is involved in DA degradation in the prefrontal cortex.

Enrollment: 32 estimated patients

Sex: All

Ages: 18 to 30 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• • Either male or female

  • Between 18 and 30 years
  • You are in good health
  • You agree to fast overnight prior to testing

Exclusion criteria

• • Are suffering from cardiac, hepatic, renal, neurological disorders

  • Damaged or diseased skin on your face and scalp, or a sensitive scalp
  • A history of alcohol or drug addiction, or severe psychiatric illness
  • Drug treatment which may lower seizure threshold (i.e. epilepsy)
  • Pregnancy
  • Sleep deprivation (less than 6 hours a day)
  • A history of migraine or headaches
  • A history of taking antidepressants
  • A history of taking tyrosine supplements

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

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32 participants in 4 patient groups

tDCS sham + placebo

Other group

Description:

tDCS= transcranial direct current stimulation drugs= placebo (cellulose \[2 grams\])

Treatment:

Combination Product: tdcs (sham/anodal) + drug (placebo/tyrosine)

tDCS sham + tyrosine

Experimental group

Description:

tDCS= transcranial direct current stimulation drugs= tyrosine (2 grams)

Treatment:

Combination Product: tdcs (sham/anodal) + drug (placebo/tyrosine)

tDCS anodal + placebo

Experimental group

Description:

tDCS= anodal transcranial direct current stimulation of the dorsolateral prefrontal cortex drugs= placebo (cellulose \[2 grams\])

Treatment:

Combination Product: tdcs (sham/anodal) + drug (placebo/tyrosine)

tDCS anodal +tyrosine

Experimental group

Description:

tDCS= anodal transcranial direct current stimulation of the dorsolateral prefrontal cortex drugs= tyrosine (2 grams)

Treatment:

Combination Product: tdcs (sham/anodal) + drug (placebo/tyrosine)