Sarcosine or D-Serine Add-on Treatment for Chronic Schizophrenia

This study has been completed.
National Science Council, Taiwan
National Health Research Institutes, Taiwan
Information provided by:
China Medical University Hospital Identifier:
First received: June 24, 2007
Last updated: NA
Last verified: June 2007
History: No changes posted

Both GlyT-1 inhibitors and NMDA-glycine site agonists have been demonstrated to be beneficial for chronic schizophrenia patients.

The purpose of this study is to compare efficacy and safety of add-on treatment of sarcosine, a GlyT-1 inhibitor, and D-serine, an NMDA-glycine site agonist, in chronically stable schizophrenia patients who have been stabilized with antipsychotics.

Condition Intervention Phase
Psychotic Disorders
Schizophrenic Disorders
Drug: Sarcosine and D-serine
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double-Blind
Primary Purpose: Treatment
Official Title: NMDA Enhancers in the Treatment of Schizophrenia: Sarcosine vs. D-Serine

Resource links provided by NLM:

Further study details as provided by China Medical University Hospital:

Primary Outcome Measures:
  • Total scores of Positive and Negative Syndrome Scale (PANSS) and Quality of Life (QOL) [ Time Frame: 6 weeks ]

Secondary Outcome Measures:
  • Subscales of PANSS [ Time Frame: 6 weeks ]

Enrollment: 60
Study Start Date: January 2005
Study Completion Date: December 2006
Detailed Description:

The etiology of schizophrenia remains unclear. Schizophrenia patients reveal positive symptoms, negative symptoms, and cognitive impairments. In addition to dopamine system hyperactivity, hypofunction of N-methyl-D-aspartate (NMDA) receptor plays a role in the pathophysiology of schizophrenia. Consequently, enhancing NMDA receptor neurotransmission has been regarded as a novel treatment approach. To date, there have been several reported trials on NMDA enhancers. Both sarcosine (N-methylglycine, a glycine transporter I inhibitor) and D-serine (a potent NMDA-glycine site agonist) showed therapeutic effects in chronically stable patients. Interestingly, sarcosine appeared more efficacious than D-serine in acutely exacerbated ones when added-on to antipsychotics. Both sarcosine and D-serine yielded excellent safety profiles.

It remains unclear whether sarcosine can be also more efficacious than D-serine in the treatment for chronically stable schizophrenia. The aim of this project is to examine the efficacy and safety of add-on treatment of sarcosine vs. D-serine in chronically stable schizophrenia patients who have been stabilized with antipsychotics.

In the study, 60-75 schizophrenic patients are recruited into the 6-week trial and randomly assigned into the three groups (2 gm/d sarcosine, 2 gm/d D-serine, or placebo) with a double-blind manner. Clinical manifestation (Positive and Negative Syndrome Scale [PANSS], side effects and quality of life (QOL) are evaluated every two weeks during the trial.. The efficacies of three groups are compared.


Ages Eligible for Study:   18 Years to 65 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Fulfill the criteria of schizophrenia according to the Diagnostic and Statistic Manual, fourth edition (DSM-IV).
  • Agree to participate in the study and provide informed consent.

Exclusion Criteria:

  • Meet DSM-IV criteria of major mood disorder, current substance dependence or mental retardation
  • History of epilepsy, head trauma or CNS diseases
  • Major, untreated medical diseases
  • Pregnancy or lactation
  Contacts and Locations
Please refer to this study by its identifier: NCT00491569

China Medical University Hospital
Taichung, Taiwan, 404
Sponsors and Collaborators
China Medical University Hospital
National Science Council, Taiwan
National Health Research Institutes, Taiwan
Principal Investigator: Hsien-Yuan Lane, MD,PhD Department of Psychiatry, China Medical University Hospital, Taiwan
  More Information

Additional publications automatically indexed to this study by Identifier (NCT Number): Identifier: NCT00491569     History of Changes
Other Study ID Numbers: NSC-94-2314-B-039-026
Study First Received: June 24, 2007
Last Updated: June 24, 2007
Health Authority: Taiwan: National Science Council

Keywords provided by China Medical University Hospital:

Additional relevant MeSH terms:
Mental Disorders
Psychotic Disorders
Schizophrenia and Disorders with Psychotic Features processed this record on April 20, 2014