Amelioration of negative symptoms in schizophrenia by glycine

Am J Psychiatry. 1994 Aug;151(8):1234-6. doi: 10.1176/ajp.151.8.1234.


Phencyclidine induces a psychotomimetic state by blocking neurotransmission at N-methyl-D-aspartic acid (NMDA) receptors. In a double-blind, placebo-controlled fashion, 14 medicated patients with chronic schizophrenia were treated with glycine, a potentiator of NMDA-receptor-mediated neurotransmission. Significant improvement in negative symptoms occurred in the group given glycine but not in the group given placebo, suggesting that potentiation of NMDA-receptor-mediated neurotransmission may represent an effective treatment for neuroleptic-resistant negative symptoms in schizophrenia.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Double-Blind Method
  • Glycine / pharmacology
  • Glycine / therapeutic use*
  • Humans
  • Male
  • Placebos
  • Receptors, N-Methyl-D-Aspartate / drug effects
  • Receptors, N-Methyl-D-Aspartate / physiology
  • Schizophrenia / drug therapy*
  • Schizophrenia / physiopathology
  • Schizophrenic Psychology*
  • Synaptic Transmission / drug effects


  • Placebos
  • Receptors, N-Methyl-D-Aspartate
  • Glycine