CSF-methionine is elevated in psychotic patients.

Cerebrospinal fluid levels of methionine (MET), homocysteine (HCY) and cystathionine were studied in patients with psychotic disorders (n=36) and in healthy controls (n=25). Patients had significantly higher MET than controls (p<0.00001), and ten of the patients had MET levels above anyone of the controls. Moreover, three young male patients had HCY levels highly above any of the controls. There were no significant gender differences in any of the parameters. Neither ageing nor neuroleptic treatment offered an explanation for the increase of MET, because also young and drug-naive patients had significantly higher MET than the controls. We conclude that patients with psychotic disorders, at least in a phase of acute exacerbation, are often in a state of disturbed one-carbon metabolism.