Private psychiatric hospital studies an Effects of L-theanine on Motor Cortex Excitability in Healthy Subjects

Photo by Sydney Sims

Butler Hospital is commencing recruitment for the clinical trial of the Effects of L-theanine on Motor Cortex Excitability in Healthy Subjects: A Paired-Pulse TMS Study.

The conditions are Cortical Excitability, Psychiatric Disorder.

A new clinical trial is recruiting patients in the following locations: United States.

The trial officially began on the June 9, 2020 and is planned to complete on May 31, 2021.

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. The investigators 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.

Among the criteria that do not allow participation, the following are indicated:

• History of significant acute or chronic neurological or medical disorder or condition that increases risk for seizure with TMS.
• History of alcohol use disorder, nicotine dependence, adjustment disorder.
• History of allergic reactions to L-theanine or green tea.
• Pregnancy.
• Unable/unwilling to abstain from nutraceutical supplements and psychotropic agents during participation in the study.
• Unable/ unwillingness to refrain from recreational substance use (e.g. alcohol or marijuana) during participation in the study/
• Meet criteria for exclusion from TMS or MRI procedures, including intracranial metal implants or nonremovable ferromagnetic items in the head/neck.

Butler Hospital is a private, non-profit, psychiatric and substance abuse hospital for children, adolescents, adults, and seniors, located at 345 Blackstone Boulevard in Providence, Rhode Island. The hospital is affiliated with the Warren Alpert Medical School of Brown University, and is the flagship for Brown University's renowned department of psychiatry. Butler Hospital was a founding member, along with Women & Infants Hospital and Kent Hospital, of the Care New England health system in 1996.

The link to the complete study profile: https://ichgcp.net/clinical-trials-registry/NCT04749745