White Matter Microsructure Abnormalities Of Late-life Depression: A Diffusion Tensor Imaging Study

Back ground: Late-onset depression (LOD) is a heterogeneous disorder that has become a major public health concern. cognitive function of depression have confirmed that the patients with depression exhibited general cognitive dysfunction. The limbic-cortical-striatal-pallidal- thalamic (LCSPT) circle is associated with mood disorders. Abnormal of white matter may disrupt the neural circle. Dysfunction of this circuit may result in apathy and alterations in emotional and autonomic responses to stimuli. Although subcortical white matter lesions hypothetically contribute to the development of depression by disrupting these or other circuits, this has not been conclusively demonstrated.Objective:1,To determine whether white matter microstructure abnormalities were assosiate with late-life depression compared with the subjects which macthed with age and similar vascular risk factor scores.2,To explore the abnormal of white matter microstructal was associate with poor executive function in depression elders.Methods:Twenty elderly depressed subjects and six-teen elderly nondepressed subjects underwent clinical assessment and diffusion tensor imaging. The authors compared results between groups while controlling for age, sex, education and vascular risk factor scores. The apparent diffusion coeffient(ADC) and fractional anisotropy(FA) were measured in regions of interest placed in the DLPFC, corpus callosum, internal capsule and occipital lobe as a control region. Executive function was assessed with the Stroop task and Verbal fluence task. Voxelwise correlational analysis was used to examine the relationship between executive function and fractional anisotropy.Results:1,The fractional anisotropy(FA) of the LOD was decreased on the ROI which placed in the DLPFC.2,Executive function was decreased in the LOD, and it associate with FA.3,Decrease of FA was associate with the course and serity of the LOD.Conclusion:1,White matter microstructure abnormalities were assosiate with late-life depression compared with the subjects which macthed with age,education,gender and similar vascular risk factor scores.2,The abnormal of white matter microstructal was associate with poor executive function in depression elders.3,The abnormal of limbic-cortical-striatal-pallidal-thalamic (LCSPT) circle could predict the seriety of depression which may be have greate value to the clinical.