Increase of phosphodiesters during neuroleptic treatment of schizophrenics: A longitudinal P-31-magnetic resonance spectroscopic study

Background: increased (PDE%) and reduced relative concentrations of phospho monoesters (PME%) have been reported in unmedicated schizophrenics, whereas findings in brain of medicated patients were not consistent. Methods: We determined in vivo the metabolism of phospholipids and high-ene rgy phosphates in the left and right frontal lobes of 8 patients with schiz ophrenia using P-31-magnetic resonance spectroscopy (P-31-MRS). Serial inve stigations were performed first after a neuroleptic-free period (mean 7.5 /- 1.9 days) and second, after neuroleptic treatment (mean 20.6 +/- 11.1 da ys), Results: PDE% increased significantly in the left frontal lobe (32.0 +/- 5. 9% versus 36.9 +/-: 5.6%, p =.009) after medication. All other parameters s howed no significant differences, Conclusions: Our study suggests that neuroleptics do not decrease phospholi pase A, activity in schizophrenia. Individual neuroleptics may have differe nt effects on phospholipase A, activity as indicated by animal studies. An influence of neuroleptics on high-energy phosphates cannot be confirmed by our data. (C) 1999 Society of Biological Psychiatry.