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Completed Early Phase 1 Interventional Accepts healthy volunteers Results available

Effects of L-theanine on Motor Cortex Excitability in Healthy Subjects: A Paired-Pulse TMS Study

ClinicalTrials.gov ID: NCT04749745

Public ClinicalTrials.gov record NCT04749745. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.

ClinicalTrials.gov public records Last synced Sep 2, 2026, 3:50 AM EDT

Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.

Official title

Effects of Single-dose L-theanine on Motor Cortex Excitability in Healthy Subjects: A Double-blinded, Randomized Order, Cross-over Paired-Pulse Transcranial Magnetic Stimulation Study

Brief summary

Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.

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.

Study identification

NCT ID
NCT04749745
Recruitment status
Completed
Study type
Interventional
Phase
Early Phase 1
Lead sponsor
Butler Hospital
Other
Enrollment
11 participants

Conditions and interventions

Eligibility (public fields only)

Age range
18 Years to 65 Years
Sex
All
Healthy volunteers
Accepts healthy volunteers

This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.

Study timeline

Start date
Jun 8, 2020
Primary completion
May 30, 2021
Completion
May 30, 2021
Last update posted
Sep 22, 2021

2020 – 2021

United States locations

U.S. sites
1
U.S. states
1
U.S. cities
1
Facility City State ZIP Site status
Butler Hospital Providence Rhode Island 02906

Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.

About this trial record page

What this page shows
Public field values for ClinicalTrials.gov record NCT04749745, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
What this page does not do
No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
Where the data comes from
Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
Last refresh
Last update posted Sep 22, 2021 · Synced Sep 2, 2026

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Open the official record

The complete protocol, eligibility criteria, and contact information for NCT04749745 live on ClinicalTrials.gov.

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