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Completed

NCT Number: NCT00491569

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

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.

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Key information

Conditions

Schizophrenias Mental Disorders Psychoses Psychotic Disorders Schizophrenia Schizophrenia Spectrum and Other Psychotic Disorders Schizophrenic Disorders

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

China Medical University Hospital

Taichung, 404, Taiwan

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Sarcosine and D-serine

Drug

Primary outcomes

  1. Total scores of Positive and Negative Syndrome Scale (PANSS) and Quality of Life (QOL)

    Time frame: 6 weeks

Secondary outcomes

  1. Subscales of PANSS

    Time frame: 6 weeks

Sponsors and collaborators

Lead sponsor

China Medical University Hospital

Other

Collaborators

  • National Health Research Institutes, Taiwan
  • National Science and Technology Council, Taiwan

Registry information

Official study title

NMDA Enhancers in the Treatment of Schizophrenia: Sarcosine vs. D-Serine

Important dates

Study start
2005
Study completion
2006
First posted
Jun 26, 2007
Registry last updated
Jun 26, 2007

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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