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Sarcosine (N-Methylglycine) Monotherapy for Schizophrenia

This study has been completed.
National Health Research Institutes, Taiwan
National Science Council, Taiwan
Information provided by:
China Medical University Hospital Identifier:
First received: May 18, 2006
Last updated: NA
Last verified: May 2006
History: No changes posted
May 18, 2006
May 18, 2006
December 2004
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Sarcosine (N-Methylglycine) Monotherapy for Schizophrenia
NMDA Enhancers in the Treatment of Schizophrenia

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 considered as a novel treatment approach. To date, there have been several trials on NMDA enhancers reported. For example, sarcosine (N-methylglycine, a glycine transporter I inhibitor) showed therapeutic effects not only in chronically stable patients but also in acutely exacerbated ones when added-on to antipsychotics. In addition, sarcosine yields excellent safety profiles, in comparison to current antipsychotics.

It remains unclear whether NMDA enhancers, such as sarcosine, can serve as monotherapy for schizophrenia. The aims of this project are to examine the efficacy and safety of sarcosine monotherapy for acutely-ill schizophrenic patients, and to compare the effects of 2 grams/day, effective dose, with 1 gram/day, ineffective lower dose.

In the study, 20 schizophrenic patients are recruited into the 6-week trial and randomly assigned into the two groups (1 g/d and 2 g/d) with a double-blind manner. Clinical manifestation (Positive and Negative Syndrome Scale; Scale for the Assessment of Negative Symptoms), side effects and quality of life are evaluated every two weeks during the trial. The efficacies of two groups are compared, and the characteristics of better responders are analyzed.
Phase 2
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double
Primary Purpose: Treatment
  • Schizophrenias
  • Psychoses
  • Psychotic Disorders
  • Schizophrenic Disorders
Drug: Sarcosine
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*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
December 2005
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Inclusion Criteria:

  • Fulfill the criteria of schizophrenia according to the Diagnostic and Statistic Manual, fourth edition (DSM-IV).
  • Free from antipsychotics for at least 7 days before enrollment.
  • 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
  • Receiving psychotropic agents or depot within three months prior to study entry
Sexes Eligible for Study: All
18 Years to 60 Years   (Adult)
Contact information is only displayed when the study is recruiting subjects
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China Medical University Hospital
  • National Health Research Institutes, Taiwan
  • National Science Council, Taiwan
Principal Investigator: Hsien-yuan Lane, MD,PhD Dept. of Psychiatry, China Medical University Hospital, Taichung, Taiwan
Study Director: Guochuan E. Tsai, MD,PhD Department of Psychiatry, Harbor-UCLA Medical Center, Torrance, California
China Medical University Hospital
May 2006

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP