Cerebrospinal fluid amino acid concentrations in chronic schizophrenia.

The concentrations of the excitatory amino acid, glutamate, the inhibitory amino acids, glycine and taurine, and the inactive amino acids, glutamine and alanine, were determined in cerebrospinal fluid samples from 12 neurological control and 17 chronic schizophrenic patients. No significant differences were observed in any amino acid between the study groups. Within the schizophrenic group, no differences were observed between paranoid and undifferentiated patients. The concentrations of these amino acids in samples obtained from six schizophrenic patients during drug-free as compared to haloperidol-treatment periods also did not differ. These results do not support the glutamate hypothesis of schizophrenia.