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We investigated the association between the Val158Met polymorphism of the catechol-O-methyltransferase (COMT) gene, the Val66Met polymorphism of the brain-derived neurotrophic factor (BDNF) gene, and white matter changes in patients with major depressive disorder (MDD) and healthy subjects using diffusion tensor imaging (DTI). We studied 30 patients with MDD (17 males and 13 females, with mean age ± standard deviation [SD] =44±12 years) and 30 sex- and age-matched healthy controls (17 males and 13 females, aged 44±13 years). Using DTI analysis with a tract-based spatial statistics (TBSS) approach, we investigated the differences in fractional anisotropy, radial diffusivity, and axial diffusivity distribution among the three groups (patients with the COMT gene Val158Met, those with the BDNF gene Val66Met, and the healthy subjects). In a voxel-wise-based group comparison, we found significant decreases in fractional anisotropy and axial diffusivity within the temporal lobe white matter in the Met-carriers with MDD compared with the controls (P<0.05). No correlations in fractional anisotropy, axial diffusivity, or radial diffusivity were observed between the MDD patients and the controls, either among those with the BDNF Val/Val genotype or among the BDNF Met-carriers. These results suggest an association between the COMT gene Val158Met and the white matter abnormalities found in the temporal lobe of patients with MDD. [ABSTRACT FROM AUTHOR]

Objective: To study the effects of treatment with atypical antipsychotic drugs on brain levels of glutamate plus glutamine in early-stage first-episode schizophrenia. Participants: Sixteen patients (eight males, eight females; aged 30 ± 11 years) completed the study. Methods: We used administered 6 months of atypical antipsychotic drugs and used proton magnetic resonance spectroscopy to evaluate the results. Results: We found that the administration of atypical antipsychotic drugs for 6 months decreased the glutamate plus glutamine/creatine ratio in the frontal lobe. These results suggest that the administration of atypical antipsychotic drugs for at least 6 months decreased glutamatergic neurotransmissions in the frontal lobe in early-stage first-episode schizophrenia, but there was no difference in frontal-lobe levels between patients and control subjects before administration. Conclusion: Taking these findings into account, the glutamatergic and GABAergic neurons are implicated in early-stage first-episode schizophrenia, but in complex ways. [ABSTRACT FROM AUTHOR]