White and Gray Matter Abnormalities in Young Adult Females with Dependent Personality Disorder: A Diffusion-Tensor Imaging and Voxel-Based Morphometry Study.

We applied diffusion-tensor imaging (DTI) including measurements of fractional anisotropy (FA), a parameter of neuronal fiber integrity, mean diffusivity (MD), a parameter of brain tissue integrity, as well as voxel-based morphometry (VBM), a measure of gray and white matter volume, to provide a basis to improve our understanding of the neurobiological basis of dependent personality disorder (DPD). DTI was performed on young girls with DPD (N = 17) and young female healthy controls (N = 17). Tract-based spatial statistics (TBSS) were used to examine microstructural characteristics. Gray matter volume differences between the two groups were investigated using voxel-based morphometry (VBM). The Pearson correlation analysis was utilized to examine the relationship between distinct brain areas of white matter and gray matter and the Dy score on the MMPI. The DPD had significantly higher fractional anisotropy (FA) values than the HC group in the right retrolenticular part of the internal capsule, right external capsule, the corpus callosum, right posterior thalamic radiation (include optic radiation), right cerebral peduncle (p < 0.05), which was strongly positively correlated with the Dy score of MMPI. The volume of gray matter in the right postcentral gyrus and left cuneus in DPD was significantly increased (p < 0.05), which was strongly positively correlated with the Dy score of MMPI (r1,2= 0.467,0.353; p1,2 = 0.005,0.04). Our results provide new insights into the changes in the brain structure in DPD, which suggests that alterations in the brain structure might implicate the pathophysiology of DPD. Possible visual and somatosensory association with motor nerve circuits in DPD.

Structural brain alterations in young adult males with narcissistic personality disorder: a diffusion tensor imaging study.

PURPOSES: 1. To find a difference in white matter (WM) between young adult males with narcissistic personality disorder (NPD) and healthy controls (HCs). 2. To find some correlations between white matter in the abnormal regions of NPD group and the pathological narcissism inventory (PNI). MATERIALS AND METHODS: Eighteen male participants with NPD (age M = 18.39, SD = 0.164; education M = 12.33, SD = 0.14) were included in our experiment. NPD participants met the DSM-IV criteria for NPD and without other personality disorders evaluated by trained clinical psychiatrists using the Structured Clinical Interview of DSM-IV for Personality Disorders (SCID-II). Moreover, healthy controls were also confirmed to be free of any axis I or II disorders and matched with education level, age and handedness (age M = 18.83 years, SD = 0.246; education M = 12.56, SD = 0.202; all participants were right handed). Those who have had major life events in the last six months, mental and physical illnesses, claustrophobia and oral implants have been excluded. We used tract-based spatial statistics (TBSS) on diffusion tensor images (DTI) and analysis of Pearson correlation between abnormal brain regions of white matter fibers and the pathological narcissism inventory. RESULTS: There was no significant difference in age and education level between NPD and HCs (p > 0.05). There were significant differences in PNI score and its subscales between NPD group and HCs (p < 0.01). Fractional anisotropy (FA) values were found decreased mainly in the right superior longitudinal fasciculus and the bilateral posterior thalamic radiation (include optic radiation). Lower axial diffusivity (AD) values were identified mostly in the left retrolenticular part of internal capsule and the left posterior thalamic radiation (include optic radiation). There existed a significant correlation between DTI data and pathological narcissism inventory. CONCLUSIONS: The decreased brain white matter microstructures among three clusters were found in the association, projection/thalamic and connection pathways of white matter in young adult males with NPD. The abnormal white matter brain regions may be one of the neuropathological basis of the pathogenesis of young males with NPD, and it may be related to white matter development in early adulthood.