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.
Drug: Sarcosine and D-serine
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Primary Purpose: Treatment
|Official Title:||NMDA Enhancers in the Treatment of Schizophrenia: Sarcosine vs. D-Serine|
- Total scores of Positive and Negative Syndrome Scale (PANSS) and Quality of Life (QOL) [ Time Frame: 6 weeks ]
- Subscales of PANSS [ Time Frame: 6 weeks ]
|Study Start Date:||January 2005|
|Study Completion Date:||December 2006|
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.
|China Medical University Hospital|
|Taichung, Taiwan, 404|
|Principal Investigator:||Hsien-Yuan Lane, MD,PhD||Department of Psychiatry, China Medical University Hospital, Taiwan|