Relationship Between BDNF Val66Met Polymorphism, Childhood Trauma And Personality Traits In Patients With Schizophrenia

Objective(1)To investigate the personality traits in patients with schizophrenia;(2)to explore the relationship between BDNF Val66Met polymorphism and the personality traits in patients with schizophrenia;(3)to explore the relationship between childhood trauma and the personality traits in patients with schizophrenia.MethodsThe venous blood samples of210patients with schizophrenia (case group) and190healthy individuals (control group) were collected. Genotyping of BDNF Val66Met polymorphism was carried out using the fluorescence resonance energy transfer method (FRET). All the samples were investigated with Tridimensional Personality Questionnaire(TPQ) and Childhood Trauma Questionnaire-Short Form(CTQ-SF). All statistical analyses were performed using SPSS19.0software. Two-sample/group t-test for comparison of personality traits between two groups, one-way ANOVA for comparison of personality traits among three groups, and chi-square test analysis were applied in discrete variables. Simple linear regression and multiple linear regressions were performed to analyze the relationship between childhood trauma and the personality traits of patients with schizophrenia.Results1. The harm-avoidance dimension scores were higher in case group than those in control group (P<0.01); the reward-dependence dimension scores were lower in case group than those in case group (P<0.01); there was no significant differences in novelty-seeking dimension between case group and control group.2. The genotype distribution and allelic frequencies of the BDNF Val66Met polymorphism were significantly different between case group and control group (P <0.01). The frequency of the BDNF Met/Met genotype was significant higher in case group (30.5%) compared with control group (21.6%).The Met allele in case group (56%) was much higher than control group (47%).3. There were no significant differences of the personality traits among patients with BDNF val/val, BDNF val/Met and BDNF Met/met genotypes in case group (P>0.05); patients with BDNF Met/Met had significantly higher scores in harm-avoidance dimension compared with patients with BDNF val/val and BDNF val/Met (P<0.05)..4. The novelty-seeking dimension scores were related to emotional abuse, sexual abuse and the CTQ-SF total scores (P<0.01).The harm-avoidance dimension scores were related to physical neglect scores of CTQ-SF (P<0.05). The reward-dependence dimension scores were significantly related to sexual abuse and the CTQ-SF total scores (P<0.05). Multivariate stepwise regression analysis found that emotional abuse was the optimum predictors for novelty-seeking dimension and CTQ-SF total score was the optimum predictors for reward-dependence dimension.Conclusions1. Patients with schizophrenia have unique personality characteristics in harm-avoidance dimension and reward-dependence dimension of TPQ.2. The BDNF Val66Met polymorphism may be involved in the etiology of schizophrenia and the Met allele may be a risk factor for developing schizophrenia.3. Patients with BDNF Met/Met genotype have unique personality characteristics in harm-avoidance dimension of TPQ compared to those with BDNF val/val and BDNF val/Mct genotypes They are more likely to be shy, nervous, depressed and fatigue.4. Childhood trauma may be one of the factors influencing the personality characteristics of schizophrenia patients.