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

Background: Increased levels of phosphodiesters (PDE%) and reduced relative concentrations of phosphomonoesters (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-energy phosphates in the left and right frontal lobes of 8 patients with schizophrenia using 31P-magnetic resonance spectroscopy (31P-MRS). Serial investigations were performed first after a neuroleptic-free period (mean 7.5 ± 1.9 days) and second, after neuroleptic treatment (mean 20.6 ± 11.1 days). 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 showed no significant differences. Conclusions: Our study suggests that neuroleptics do not decrease phospholipase A2 activity in schizophrenia. Individual neuroleptics may have different effects on phospholipase A2 activity as indicated by animal studies. An influence of neuroleptics on high-energy phosphates cannot be confirmed by our data.