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NCT04749745 · ClinicalTrials.gov registry record · Early Phase 1
Effects of L-theanine on Motor Cortex Excitability in Healthy Subjects: A Paired-Pulse TMS Study
A Early Phase 1 study, sponsored by Butler Hospital.
- Completed
- Registry status
- Early Phase 1
- Development phase
- 11
- Enrollment target
NCT04749745: Completed Early Phase 1 study, sponsored by Butler Hospital.
NCT04749745 is a Early Phase 1 study that has completed, run by Butler Hospital. The registered enrollment target is 11 participants, below the 53-participant average among 2,764 other Early Phase 1 trials with a reported enrollment target (79% lower). According to ClinicalTrials.gov, the official US trial registry.
The verdict
NCT04749745, a Early Phase 1 study, has completed, sponsored by Butler Hospital.
- COMPLETED
- Registry status
- Early Phase 1
- Development phase
- 11 participants
- Enrollment target
Study Summary
Major depressive disorder (MDD) is a serious mental illness and the leading cause of disability worldwide. New pharmacotherapeutic agents with complementary neurobiological mechanism and better side effect profile are of great needs. In addition to the monoamine system, the glutamatergic system plays a crucial role in MDD. L-theanine (N5-ethyl-L-glutamine) is the primary psychoactive component uniquely in green tea. Preclinical studies have demonstrated anti-depressant effect of L-theanine in rodents and provided evidences for its pharmacological properties of N-methyl-D-aspartate (NMDA) and gamma-aminobutyric acid (GABA) agonism. Yet these effects have not been proven in humans. Only one open-label clinical trial has studied and supported antidepressant effects of L-theanine in MDD patients. We propose using pair-pulse transcranial magnetic stimulation (ppTMS) to probe how L-theanine may manipulate the glutamatergic and GABA systems in the frontal region by changing cortical excitability first in healthy subjects. We plan to investigate the neurobiological effects of L-theanine in healthy subjects first. Granted that the first phase pilot trial provides neurophysiological evidence of L-theanine on motor cortex excitability in human subjects, next phases of studies on L-theanine in MDD patients cortical excitability could be justified.
Primary Outcome
The changes of Short-interval Intracortical Inhibition (SICI), Intracortical Facilitation (ICF), and Long-interval Intracortical Inhibition (LICI) before and 30 minutes after each drug administration. SICI, ICF and LICI are paired-pulse TMS (ppTMS)-EMG outcome measures that assess the activity of motor cortex GABA-A, NMDA and GABA-B interneurons, respectively. They are measured by the ratio between the peak-to-peak amplitude of motor-evoked potential (MEP) elicited by a testing TMS pulse (120%
Interventions
- DRUG Placebo
- DRUG L-theanine
Trial Details
| Field | Value |
|---|---|
| Enrollment Target | 11 participants |
| Start Date | 2020-06-09 |
| Est. Completion | 2021-05-31 |
| Phase | Early Phase 1 |
What the finished NCT04749745 record still lists
NCT04749745 is an interventional study that assigns participants to a tested intervention. The registry caps enrollment at 11 participants, a relatively small participant target, below the 53-participant average among 2,764 other Early Phase 1 trials with a reported enrollment target (79% lower).
The record links to 0 conditions, and to 2 interventions - of which Placebo is the first listed.
NCT04749745 does not publish any study locations in the registry export this page uses.
Frequently Asked Questions
What is clinical trial NCT04749745 about?
NCT04749745 is a clinical study titled "Effects of L-theanine on Motor Cortex Excitability in Healthy Subjects: A Paired-Pulse TMS Study". Major depressive disorder (MDD) is a serious mental illness and the leading cause of disability worldwide. New pharmacotherapeutic agents with complementary neurobiological mechanism and better side effect profile are of great needs. In addition to the monoamine system, the glutamatergic system play...
What is the current status of trial NCT04749745?
This trial is currently completed. It is a Early Phase 1 study. The enrollment target is 11 participants. The study started on 2020-06-09. Estimated completion is 2021-05-31.
What interventions are being tested in trial NCT04749745?
The interventions under investigation include: Placebo (DRUG), L-theanine (DRUG).
Who is sponsoring clinical trial NCT04749745?
This trial is sponsored by Butler Hospital, which has 103 total clinical trials registered on ClinicalTrials.gov.
Learn More About Clinical Trials
How this trial's enrollment target compares
Where NCT04749745's enrollment target sits among peer trials
11 1601st of 2000 higher than 373 of 2,000 other Early Phase 1 trials
participants (enrollment target), bucketed by value
Each bar is a band; taller bars hold more other Early Phase 1 trials. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source ClinicalTrials.gov registry export · 2026-08-08
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