Modulation of Cognitive Flexibility by Transcranial Direct Current Stimulation, Tyrosine Administration and Polymorphisms in the COMT GeneNCT03845920
Mod of Cognitive Flexibility by tDCS, Tyrosine Polymorphisms in the COMT Gene
A study of Modulation of Cognitive Flexibility by Transcranial Direct Current Stimulation, Tyrosine Administration and Polymorphisms in the COMT Gene, run by Sheffield Hallam University at 1 site in United Kingdom.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 to 30 yearsHealthy volunteers can take part
- Conditions the study is for
- Modulation of Cognitive Flexibility by Transcranial Direct Current Stimulation, Tyrosine Administration and Polymorphisms in the COMT Gene
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 32 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 18 Feb 2019to 30 Sep 2019
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 30 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- • Either male or female
- Between 18 and 30 years
- You are in good health
- You agree to fast overnight prior to testing
Who cannot join
- • 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)
Show all 9Show fewer
- A history of migraine or headaches
- A history of taking antidepressants
- A history of taking tyrosine supplements
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site, 1 recruiting
- Recruiting
Psychology labs
Sheffield, South Yorkshire, S10 2BQ
Lee Wallace, BSc, 0114 225 ext. 5953, l.j.wallace@shu.ac.uk
Jordan Crawford, MSc, 0114 225 ext. 3554, j.d.crawford@shu.ac.uk
About this study
Official title: Modulation of Cognitive Flexibility by Transcranial Direct Current Stimulation, Tyrosine Administration and Polymorphisms in the COMT Gene
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.
- Being tested
- tdcs (sham/anodal) + drug (placebo/tyrosine)
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
tdcs (sham/anodal) + drug (placebo/tyrosine)Combination product
tDCS= A DC Stimulator Plus (neuroConn, Germany) with one 5 cm x 7 cm rubber electrode (anode) and a 10 cm x 10 cm (cathode; reference electrode), encased in saline soaked sponges will be used. The anode will be positioned over the left dlPFC, centered on F3 in the 10e20 electroencephalography (EEG) system, while the cathode on the contralateral supraorbital ridge (Fp2).Current will be delivered at 1.5mA for 20 min plus 30 s fade in/fade out periods.For sham stimulation, the current will be faded in over 30 s, at 1.5mA and then will be switched off.
Drugs= 2.0 g of L-Tyrosine and 2.0 g of the placebo microcrystalline cellulose will be dissolved in 400ml of orange juice as per previously published protocols.
| Study group | Role | What they receive |
|---|---|---|
| tDCS sham + placebo | Other | tDCS= transcranial direct current stimulation drugs= placebo (cellulose [2 grams]) Receives: Combination Product: tdcs (sham/anodal) + drug (placebo/tyrosine) |
| tDCS sham + tyrosine | Experimental | tDCS= transcranial direct current stimulation drugs= tyrosine (2 grams) Receives: Combination Product: tdcs (sham/anodal) + drug (placebo/tyrosine) |
| tDCS anodal + placebo | Experimental | tDCS= anodal transcranial direct current stimulation of the dorsolateral prefrontal cortex drugs= placebo (cellulose [2 grams]) Receives: Combination Product: tdcs (sham/anodal) + drug (placebo/tyrosine) |
| tDCS anodal +tyrosine | Experimental | tDCS= anodal transcranial direct current stimulation of the dorsolateral prefrontal cortex drugs= tyrosine (2 grams) Receives: Combination Product: tdcs (sham/anodal) + drug (placebo/tyrosine) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Wisconsin Card Sorting Test (WCST) performance
Measuring change in perseverative errors in the WCST
Measured: Measured twice in each session (4 arms): at time 0 and 80 minutes into testing.
Probabilistic Reversal Learning (PRL) performance
Measuring change in reversal errors in the WCST
Measured: Measured twice in each session (4 arms): at time 0 and 80 minutes into testing.
Flanker Task performance
Measuring change in conflict cost (defined as the difference in reaction time between congruent and incongruent responses)
Measured: Measured twice in each session (4 arms): at time 0 and 80 minutes into testing.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Feb 2019
- Study start18 Feb 2019
- Primary completion30 Sep 2019 (estimated)
- Study completion30 Sep 2019 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Modulation of Cognitive Flexibility by Transcranial Direct Current Stimulation, Tyrosine Administration and Polymorphisms in the COMT GeneStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 32 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Sheffield Hallam University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Luca Aquili, Ph.D., Principal investigator, Sheffield Hallam University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03845920
- Sponsor's protocol ID
- SheffieldHallamAquili2019
- Status last verified
- Apr 2019
- First submitted
- 11 Feb 2019
- Last updated
- 4 Apr 2019
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 4 Apr 2019. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Modulation of Cognitive Flexibility by Transcranial Direct Current Stimulation, Tyrosine Administration and Polymorphisms in the COMT Gene
- ClinicalTrials.gov ID
- NCT03845920
- Acronym / sponsor ID
- SheffieldHallamAquili2019
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 32 participants (estimated)
- Lead sponsor
- Sheffield Hallam UniversityUniversity, hospital or other
- Study start
- 18 Feb 2019 (actual)
- Primary completion
- 30 Sep 2019 (estimated)
- Study completion
- 30 Sep 2019 (estimated)
- First posted
- 19 Feb 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| tDCS sham + placebo | Other | Combination Product: tdcs (sham/anodal) + drug (placebo/tyrosine)tDCS= transcranial direct current stimulation drugs= placebo (cellulose [2 grams]) |
| tDCS sham + tyrosine | Experimental | Combination Product: tdcs (sham/anodal) + drug (placebo/tyrosine)tDCS= transcranial direct current stimulation drugs= tyrosine (2 grams) |
| tDCS anodal + placebo | Experimental | Combination Product: tdcs (sham/anodal) + drug (placebo/tyrosine)tDCS= anodal transcranial direct current stimulation of the dorsolateral prefrontal cortex drugs= placebo (cellulose [2 grams]) |
| tDCS anodal +tyrosine | Experimental | Combination Product: tdcs (sham/anodal) + drug (placebo/tyrosine)tDCS= anodal transcranial direct current stimulation of the dorsolateral prefrontal cortex drugs= tyrosine (2 grams) |
Who may qualify
- Ages
- 18 to 30 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- • Either male or female
Key exclusion criteria (9 listed)
- • Are suffering from cardiac, hepatic, renal, neurological disorders
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| tdcs (sham/anodal) + drug (placebo/tyrosine)tDCS= A DC Stimulator Plus (neuroConn, Germany) with one 5 cm x 7 cm rubber electrode (anode) and a 10 cm x 10 cm (cathode; reference electrode), encased in saline soaked sponges will be used. The anode will be positioned over the left dlPFC, centered on F3 in the 10e20 electroencephalography (EEG) system, while the cathode on the contralateral supraorbital ridge (Fp2).Current will be delivered at 1.5mA for 20 min plus 30 s fade in/fade out periods.For sham stimulation, the current will be faded in over 30 s, at 1.5mA and then will be switched off. Drugs= 2.0 g of L-Tyrosine and 2.0 g of the placebo microcrystalline cellulose will be dissolved in 400ml of orange juice as per previously published protocols. | Combination product | tDCS anodal + placebo, tDCS anodal +tyrosine, tDCS sham + placebo, tDCS sham + tyrosine |
Primary outcome
Wisconsin Card Sorting Test (WCST) performance
Time frame: Measured twice in each session (4 arms): at time 0 and 80 minutes into testing.
Measuring change in perseverative errors in the WCST
Probabilistic Reversal Learning (PRL) performance
Time frame: Measured twice in each session (4 arms): at time 0 and 80 minutes into testing.
Measuring change in reversal errors in the WCST
Flanker Task performance
Time frame: Measured twice in each session (4 arms): at time 0 and 80 minutes into testing.
Measuring change in conflict cost (defined as the difference in reaction time between congruent and incongruent responses)
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Apr 2019.
- Individual participant dataSharing planned: No
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Luca Aquili, Ph.D. principal investigator
Sheffield Hallam University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study of Modulation of Cognitive Flexibility by Transcranial Direct Current Stimulation, Tyrosine Administration and Polymorphisms in the COMT Gene, run by Sheffield Hallam University at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: status not confirmed, as of the sponsor's last update on 4 Apr 2019. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Luca Aquili, Ph.D. (+ 44 (0) 114 225 ext. 6991, luca.aquili@shu.ac.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Wisconsin Card Sorting Test (WCST) performance (time frame: Measured twice in each session (4 arms): at time 0 and 80 minutes into testing.). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Apr 2019.