White Matter Abnormalities In Paranoid Personality Disorder:a Diffusion Tensor Imaging Study

Aim:A randomized controlled trial was carried out where our objective was to investigate whether differences exist for brain white matter fractional anisotropy(FA)values and mean diffusivity(MD)values between paranoid personality disorder(PPD)and healthy control group aged between 19 and 22 years old.We wanted to find out the location of white matter lesion that may exist in the early stages of paranoid schizophrenia and thus,provide an "early developmental abnormalities hypothesis"for paranoid schizophrenia.Subjects:1100 male freshmen who enrolled in Dalian University of Technology in September 2015 were selected.All of them filled the Minnesota Multiphasic Personality Inventory(MMPI).Informed consent was obtained from each participant.On the basis of descending order of the paranoid(Pa)factor scores,30 individuals of high scores(Pa≥60)were screened out.Out of these,after assessment by two experienced psychiatrists,only 16 met the diagnostic criteria of the fifth edition of Diagnostic and Statistical Manual of Mental Disorders(DSM-V)for paranoid schizophrenia.Then,11 subjects were randomly selected from the 16 to participate in the experiment.They had a mean age of 19.45±0.52 years and a mean level of education of 12.00±0.00 years.Matched 11 healthy personality freshmen were then selected as the healthy control group.Methods:All the 22 subjects were scanned using SIEMENS 3.0 Tesla superconducting magnetic resonance scanning imaging system and the diffusion tensor imaging data of all the participants was recorded.FA values and MD values of brain white matter fibers in PPD group and control group were obtained by Tract-based spatial statistic technique.T test method was used to compare whether differences between PPD group and healthy control group in FA values and MD values exist.Using Pearson correlation analysis,correlation between FA values and MD values of all divergence brain regions of PPD group and the Pa factor scores of MMPI were analyzed.Results:1.No significant differences(p>0.05)were observed between PPD group and control group in relation to age and level of education.2.Compared to control group,the PPD group had significant lower FA values in genu of corpus callosum(CC),left posterior thalamic radiation(PTR,L)and right anterior corona radiata(ACR,R).In the control group,there was no significant increase or decrease in other brain regions compared to the PPD group.3.There was no significant difference in MD values between PPD group and control group.4.There was no significant correlation between all divergence brain regions of PPD and Pa factor scores of MMPI.Conclusion:In this study,performing diffusion tensor imaging technique and using TBSS as our analysis tool,we found that brain white matter microstructure of paranoid personality disorder individuals have changes in corpus callosum,corona radiata and thalamic radiation.We thus speculate that the neuropathological basis of early onset paranoid personality disorder may be related to aforementioned brain regions.This may be due to a problem in the process of development and therefore suggest that abnormal white matter is most probably one of the basis of neuropathology in the early stages of paranoid personality disorder.