A Multicenter, Add-On Randomized Controlled Trial of Low-Dose <span style="font-variant:small-caps;">d</span>-Serine for Negative and Cognitive Symptoms of Schizophrenia
J Clin Psychiatry 2012;73(6):e728-e734
© Copyright 2017 Physicians Postgraduate Press, Inc.
Purchase This PDF for $40.00
If you are not a paid subscriber, you may purchase the PDF.
(You'll need the free Adobe Acrobat Reader.)
Receive immediate full-text access to JCP. You can subscribe to JCP online-only ($86) or print + online ($156 individual).
With your subscription, receive a free PDF collection of the NCDEU Festschrift articles. Hurry! This offer ends December 31, 2011.
If you are a paid subscriber to JCP and do not yet have a username and password, activate your subscription now.
As a paid subscriber who has activated your subscription, you have access to the HTML and PDF versions of this item.
Click here to login.
Did you forget your password?
Still can't log in? Contact the Circulation Department at 1-800-489-1001 x4 or send email
Background: Observations that antagonists of the N-methyl-D-aspartate (NMDA) receptor of glutamatergic neurons can mimic symptoms of schizophrenia have raised the hope that NMDA agonists can improve symptoms. On the basis of encouraging results of trials in which NMDA agonists were added to antipsychotics, we conducted an adequately powered randomized controlled trial adding D-serine, an NMDA modulator, to antipsychotics.
Method: This study was a 195-patient, multicenter, double-blind, randomized, placebo-controlled, 16-week trial of d-serine 2 g/d as an add-on treatment to antipsychotics. Subjects had DSM-IV schizophrenia or schizoaffective disorder and were inpatients or outpatients stabilized on antipsychotics, with persistent negative symptoms. The primary outcome measures were changes in negative symptoms and cognition as measured by the Scale for the Assessment of Negative Symptoms (SANS) and the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) battery, respectively. The study was performed between 2003 and 2007.
Results: Mean total Positive and Negative Syndrome Scale scores at baseline were 75.5. Subjects receiving d-serine and placebo improved in scores on the SANS and MATRICS, but no significant differences were observed between groups: improvement on SANS was 11.4% for d-serine vs 14.8% for placebo, F1,147=1.18, P=.32; and improvement on MATRICS was 6.8% for d-serine vs 6.1% for placebo, F1,125=0.96, P=.39, respectively. D-Serine was well tolerated.
Discussion:This study did not find a significant difference between drug and placebo. However, the results are limited by a relatively large placebo response and somewhat lower-achieved doses than in prior studies. Future studies will administer higher doses and will attempt to affect the NMDA receptor using other mechanisms, such as agonists of the presynaptic metabotropic glutamate 2/3 receptor or glycine reuptake inhibitors.
Trial Registration: ClinicalTrials.gov identifier: NCT00138775
J Clinical Psychiatry 2012; 73(6): 728-734
© 2012 Physicians Postgraduate Press, Inc.