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Completed Phase 2Phase 3 Interventional Accepts healthy volunteers Results available

Tryptophan MRI in People With Schizophrenia and Healthy Controls

ClinicalTrials.gov ID: NCT02067975

Public ClinicalTrials.gov record NCT02067975. 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 1, 2026, 7:51 PM EDT

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

Official title

Neuroimaging of Tryptophan Challenge in People With Schizophrenia and Healthy Controls

Brief summary

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

Kynurenic acid (KYNA) is a naturally occurring chemical in the brain. Studies with rodents indicate that levels of KYNA can impact levels of the neurotransmitters glutamate and dopamine. One way to reliably increase KYNA levels is by ingesting the amino acid tryptophan. Tryptophan is a normal part of the human diet. Tryptophan gets metabolized/changed to other chemicals in the body- including KYNA. By giving people 6 grams of tryptophan, the investigators will be able to increase the KYNA level in a controlled way. The investigators will then be able to study the effects of KYNA on neurotransmitters by using cognitive tests and magnetic resonance imaging techniques (measuring brain activity and brain chemistry using the MRI magnet). They will test people using tryptophan and also using a placebo to look for differences. The investigators will test healthy controls and people with schizophrenia to look for differences.

Study identification

NCT ID
NCT02067975
Recruitment status
Completed
Study type
Interventional
Phase
Phase 2, Phase 3
Enrollment
93 participants

Conditions and interventions

Conditions

Interventions

Drug

Eligibility (public fields only)

Age range
18 Years to 55 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
Aug 13, 2014
Primary completion
Dec 30, 2019
Completion
Dec 30, 2019
Last update posted
Jul 29, 2024

2014 – 2019

United States locations

U.S. sites
1
U.S. states
1
U.S. cities
1
Facility City State ZIP Site status
Maryland Psychiatric Research Center Catonsville Maryland 21228

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 NCT02067975, 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 Jul 29, 2024 · Synced Sep 1, 2026

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Open the official record

The complete protocol, eligibility criteria, and contact information for NCT02067975 live on ClinicalTrials.gov.

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