Folate, homocysteine, and negative symptoms in schizophrenia.
OBJECTIVE
Because glutamate carboxypeptidase II (GCPII) regulates both folate absorption and activation of N-methyl-d-aspartic acid receptors, the authors examined relationships between serum folate concentrations and clinical symptoms in schizophrenia patients.


METHODS
For 91 outpatients with schizophrenia, clinical assessments were performed and serum folate, homocysteine, B(12), glycine, and serine concentrations were measured.


RESULTS
Serum folate concentrations were significantly lower than in a representative sample from the Framingham Offspring Study. Folate concentration correlated inversely with the Scale for Assessment of Negative Symptoms total score and was lower in patients with the deficit syndrome than in nondeficit patients. Homocysteine concentration correlated with the severity of extrapyramidal symptoms.


CONCLUSIONS
These findings could reflect several possible mechanisms, including low dietary intake of folate, low GCPII activity, cigarette smoking, and the involvement of folate in the synthesis of neurotransmitters. Additional studies are needed to clarify these findings.
Goff
Donald C
DC
Schizophrenia Program and Neurology Service, Massachusetts General Hospital, Boston, USA. goff@psych.mgh.harvard.edu
Bottiglieri
Teodoro
T
Arning
Erland
E
Shih
Vivian
V
Freudenreich
Oliver
O
Evins
A Eden
AE
Henderson
David C
DC
Baer
Lee
L
Coyle
Joseph
J
D000328:Adult; D000553:Ambulatory Care; D001480:Basal Ganglia Diseases / Q000139:chemically induced / Q000175:diagnosis; D004032:Diet / Q000009:adverse effects; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage / Q000097:blood*; D043425:Glutamate Carboxypeptidase II / Q000097:blood; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000097:blood* / Q000175:diagnosis*; D012565:Schizophrenic Psychology; D012720:Severity of Illness Index; D012907:Smoking / Q000097:blood; D014805:Vitamin B 12 / Q000097:blood
D006710:Homocysteine; D005492:Folic Acid; D043425:Glutamate Carboxypeptidase II; D014805:Vitamin B 12