[A volumetric study of brain structures in subtypes of depression].

The aim of this study is to compare the volumes of hippocampus, amygdala and subgenual prefrontal cortex among patients with melancholic depression, patients with psychotic depression and normal controls. Thirty nine patients with a diagnosis of major depression (22 with melancholic and 17 with psychotic subtype) and 18 normal controls were included in the study. Hippocampal, amygdala, anterior and posterior subgenual cortex volumes were measured by manual tracings on magnetic resonance volumetric images and compared across the 3 groups. We identified larger amygdala volumes and smaller left anterior subgenual cortex volumes in both patient groups compared to controls. There were no differences in hippocampal, right anterior and posterior subgenual cortex volumes across the 3 groups. In conclusion, melancholic and psychotic depression were not differentiated regarding the volumes of the hippocampus, the amygdala, and anterior and posterior subgenual cortex, even though amygdala volumes and left anterior subgenual cortex volume of both patient groups were differentiated compared to controls.

Association of serum BDNF levels with hippocampal volumes in first psychotic episode drug-naive schizophrenic patients.

Evidence suggests that hippocampal volumetric abnormalities are present in first-episode schizophrenia. The hippocampus contains the highest brain levels of neurotrophic factors, which are major determinants of neuronal plasticity. Brain-derived neurotrophic factor (BDNF) influences neuronal survival, differentiation, synaptogenesis, and maintenance and is also correlated with neuronal activation in the hippocampus. BDNF is also involved in the development and modulation of dopaminergic-related systems. Alterations of serum BDNF levels have been shown in a number of studies with first episode patients with schizophrenia, probably reflecting an association between BDNF and the pathogenesis of the disorder. In the present study we investigated the correlation between serum BDNF levels and hippocampal volumes in a sample of first episode drug-naïve patients with schizophrenia (FEP) and healthy control subjects. We found that hippocampal volume (HV) was decreased in FEP patients. Corrected right HV of FEP patients were significantly smaller compared to corrected right HVs of healthy subjects. The serum BDNF levels in the sample of FEP patients was significantly reduced compared to the healthy subjects. A significant positive association was found between serum BDNF and the corrected right HV in the group of patients such that the smaller the HV, the more reduced the serum BDNF levels. (Pearson r=0.452, p=0.045). Our findings indicate that low serum BDNF levels are associated with reduction in HV at the onset of schizophrenia and may further support the theory of a neuroprogressive-neurotoxic reaction associated with the onset of psychosis.