Glycine and D-Cycloserine in Schizophrenia

Withdrawn before enrolling · Phase 3 · Has a placebo group

Conditions studied: Schizophrenia

In brief

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.

Key facts

Study ID

NCT00000372

Run by

Massachusetts General Hospital

People needed

0

Starts

1998-03-01

Expected to finish

2005-11-01

Last updated by the study team

2014-06-12

Who can join

Age: 18 and older, up to 65. Sex: any. Healthy volunteers: not accepted.

You may qualify if…

• Diagnosis of Schizophrenia
• Score of 27 or greater on the Scale for the Assessment of Negative Symptoms (SANS)
• Treatment with stable dose of clozapine for at least 4 weeks
• Between 18 and 65 years old

You may not qualify if…

• No other antipsychotic medications in oral for for at least 3 months or in depot form for 6 months
• Current major depressive episode
• Current substance abuse diagnosis

Where it is running

• Freedom Trail Clinic — Boston, Massachusetts, United States

Full record on ClinicalTrials.gov

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