Placebo-controlled trial of glycine added to clozapine in schizophrenia.
OBJECTIVE
The purpose of this study was to evaluate the effects of high-dose oral glycine on positive and negative symptoms and cognitive function when added to clozapine in adults with schizophrenia.


METHODS
The authors conducted a double-blind, placebo-controlled, parallel-group trial of 60 g/day of glycine added to clozapine for 8 weeks in 30 adults with schizophrenia. Clinical ratings were performed every 2 weeks.


RESULTS
Twenty-seven patients completed the trial. Glycine augmentation of clozapine produced no statistically significant change in positive or negative symptoms or cognitive functioning. No subjects showed clinically significant worsening of clinical ratings.


CONCLUSIONS
These data, combined with data from previous trials with D-cycloserine and glycine, suggest that agonists at the glycine site may be less effective when combined with clozapine than they are when combined with conventional antipsychotics.
Evins
A E
AE
The Psychotic Disorders Unit of the Massachusetts General Hospital, Boston, MA, USA. a_eden_evins@hms.harvard.edu
Fitzgerald
S M
SM
Wine
L
L
Rosselli
R
R
Goff
D C
DC
D000328:Adult; D000553:Ambulatory Care; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D003024:Clozapine / Q000627:therapeutic use*; D003072:Cognition Disorders / Q000188:drug therapy / Q000523:psychology; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D005998:Glycine / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D010919:Placebos; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012559:Schizophrenia / Q000175:diagnosis / Q000188:drug therapy*; D012565:Schizophrenic Psychology; D016896:Treatment Outcome
D014150:Antipsychotic Agents; D010919:Placebos; D003024:Clozapine; D005998:Glycine