Biochemical changes in the cingulum in patients with schizophrenia and chronic bipolar disorder.

Biochemical changes have been reported in vivo in the brain in schizophrenia patients using 1H-magnetic resonance spectroscopy (MRS). The aim of this study was to assess the specificity of biochemical changes occurring in schizophrenia patients, in a direct comparison with bipolar disorder patients. Fourteen patients with chronic paranoid schizophrenia, 17 euthymic type I bipolar patients with no previous history of psychotic symptoms and 15 healthy controls were included, most of them were female. They underwent a study with MRS: proton spectra were acquired using a Signa 1.5 T CVI scanner, with a localised single voxel PRESS sequence. N-acetyl aspartate (NAA), Creatine (Cr), and Choline (Cho) metabolite resonance intensities were all quantified in the cingulum, a region of interest in schizophrenia and bipolar disorder. Schizophrenia patients showed a significantly higher Cho/Cre as well as lower NAA/Cho ratios as compared with controls and bipolar patients. No significant differences were found among the three groups as regards NAA/Cre levels. These data are consistent with an increase in the concentration of choline in the cingulum in chronic schizophrenia, at least in this predominantly female group. Such an increase seems to be more intense than in psychosis-free bipolar disorder patients.