Abnormal Regional Homogeneity And Its Correlations With Personality In First-Episode, Treatment-Naive Somatization Disorder

Background:Structural and functional abnormalities of the default mode network and their correlations with personality have been found in somatization disorder. However, no study is conducted to identify regional neural activity and its correlations with personality in somatization disorder. Our research mainly investigated the:(1) regional homogeneity (ReHo) approach was applied to explore whether abnormal regional neural activity is present in patients with somatization disorder. (2) the relationship between the abnormal regional neural activity and the personality measured by Eysenck Personality Questionnaire (EPQ) in patients with somatization disorder.Methods:1. Twenty-six first-episode, treatment-naive patients with somatization disorder and 30 sex-, age-, and education-matched healthy controls participated in the study. All patients were diagnosed based on the Structured Clinical Interview of the DSM-IV (SCID).2. At the scan day, all subjects were assessed with EPQ to measure personality dimensions. Hamilton depression scale (HAMD), Hamilton anxiety scale (HAMA) and the somatization subscale of SCL-90 were respectively applied to assess the severity of depression, anxiety and somatic symptoms.3. Statistical parametric mapping software was used to preprocess image. A ReHo approach was employed to analyze the data. Linear correlations were conducted between abnormal ReHo values and age, course of disease, education level, symptom severity, and the domains of EPQ (extraversion, psychoticism, and lie).Results:1. The scores of HAMD, HAMA and somatization subscale scores of SCL-90 in somatization disorder patients group are respectively 18.84±7.31, 22.96 ±10.95,28.48±10.37. Compared with healthy controls, patients with somatization disorder showed higher levels of depression, anxiety and somatic symptoms (p<0.001).2. Compared with healthy controls, the somatization disorder group had a significantly increased ReHo in the left angular gyrus.3. The increased ReHo positively correlated to the neuroticism scores of EPQ (EPQ-N). No other correlations were detected between the ReHo values and other related factors, such as education level, HAMA, HAMD and symptom severity.Conclusions:1.Our results suggest that abnormal regional neural activity of the default mode network may play a key role in somatization disorder with clinical implications, and emphasize the importance of the default mode network in the pathophysiological process of somatization disorder.2. Significantly positive correlation between increased ReHo in the left AG and the scores of EPQ-N was found in the patient group. The increased ReHo in the left angular gyrus may provide new evidence for the correlations between personality and somatization disorder.