Independent directory Public ClinicalTrials.gov records United States
ClinicalTrials.gov record
Withdrawn Phase 3 Interventional

Glycine and D-Cycloserine in Schizophrenia

ClinicalTrials.gov ID: NCT00000372

Public ClinicalTrials.gov record NCT00000372. 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 3, 2026, 12:26 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

A Placebo Controlled Trial of Glycine Added to Clozapine in Schizophrenia

Brief summary

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

The purpose of this study is to compare the effects of D-cycloserine and glycine for treating negative symptoms (such as loss of interest, loss of energy, loss of warmth, and loss of humor) which occur between phases of positive symptoms (marked by hallucinations, delusions, and thought confusions) in schizophrenics. Clozapine is currently the most effective treatment for negative symptoms of schizophrenia. Two other drugs, D-cycloserine and glycine, are being investigated as new treatments. D-cycloserine improves negative symptoms when added to some drugs, but may worsen these symptoms when given with clozapine. Glycine also improves negative symptoms and may still be able to improve these symptoms when given with clozapine. This study gives either D-cycloserine or glycine (or an inactive placebo) with clozapine to determine which is the best combination. Patients will be assigned to 1 of 3 groups. Group 1 will receive D-cycloserine plus clozapine. Group 2 will receive glycine plus clozapine. Group 3 will receive an inactive placebo plus clozapine. Patients will receive these medications for 8 weeks. Negative symptoms of schizophrenia will be monitored through the Scale for the Assessment of Negative Symptoms, Positive symptoms will be monitored through the Positive and Negative Syndrome Scale, and additionally subjects will complete the Brief Psychiatric Rating Scale and the Global Assessment Scale. An individual may be eligible for this study if he/she is 18 to 65 years old and has been diagnosed with schizophrenia.

Study identification

NCT ID
NCT00000372
Recruitment status
Withdrawn
Study type
Interventional
Phase
Phase 3
Enrollment
Not listed

Conditions and interventions

Conditions

Interventions

Drug

Eligibility (public fields only)

Age range
18 Years to 65 Years
Sex
All
Healthy volunteers
Healthy volunteers not accepted

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

Study timeline

Start date
Feb 28, 1998
Primary completion
Oct 31, 2005
Completion
Oct 31, 2005
Last update posted
Jun 11, 2014

1998 – 2005

United States locations

U.S. sites
1
U.S. states
1
U.S. cities
1
Facility City State ZIP Site status
Freedom Trail Clinic Boston Massachusetts 02114

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 NCT00000372, 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 Jun 11, 2014 · Synced Sep 3, 2026

Related: full search, browse by condition, browse by drug or therapy, browse by sponsor, browse by U.S. city.

Open the official record

The complete protocol, eligibility criteria, and contact information for NCT00000372 live on ClinicalTrials.gov.

View official ClinicalTrials.gov record →