AMELIORATION OF NEGATIVE SYMPTOMS IN SCHIZOPHRENIA BY GLYCINE

Phencyclidine induces a psychotomimetic state by blocking neurotransmi ssion at N-methyl-D-aspartic acid (NMDA) receptors. In a double-blind, placebo-controlled fashion, 14 medicated patients with chronic schizo phrenia were treated with glycine, a potentiator of NMDA- receptor-med iated 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 neurotransmis sion may represent an affective treatment for neuroleptic-resistant ne gative symptoms in schizophrenia.