title: Personality traits as an endophenotype in genetic studies on suicidality in bipolar disorder.
abstract: Introduction The influence of personality traits on suicidal behaviour risk has been well documented. Personality traits and suicidal behaviour are partially genetically determined and personality has been described as an endophenotype of suicidal behaviour. The aim of this study was to investigate a possible association between personality traits with suicidal behaviour and selected serotonergic gene polymorphisms.
  
  
  METHODS
  In the study we included 156 patients meeting DSM-IV criteria for bipolar disorder (BP) and 93 healthy controls. The personality dimensions were assessed using the Temperament and Character Inventory (TCI). We genotyped two selected polymorphisms of the tryptophan hydroxylase 1 (TPH1) gene (rs1800532 218A>C and rs1799913 779A>C) and polymorphism in the promoter region of serotonin transporter gene (5-HTTLPR, rs25531) related to serotoninergic neurotransmission. Multiple poisson regression, logistic regression and Kruskal-Wallis tests were applied.
  
  
  RESULTS
  We found numerous differences between the BP patients and the control group in terms of their TCI dimensions/subdimensions. Significant differences were found between patients with, and without, suicidal attempts in fatigability and asthenia (Ha4), as well as in harm avoidance (Ha). We also found that the interactions between TCI subdimensions (the interaction of disordiness (Ns4) and spiritual acceptance (St3), disordiness (Ns4) and integrated conscience (C5), extravagance (Ns3) and resourcefulness (Sd3)) were significantly contributing for suicidal behaviour risk. We found association between all studied genetic polymorphisms and several TCI dimensions and subdimensions.
  
  
  CONCLUSIONS
  Our results confirm that personality traits are partially determined by genes. Both personality traits and the interactions between temperament and character traits, may be helpful in predicting suicidal behaviour.
authors: 1Psychiatric Genetics Unit,Department of Psychiatry,Poznan University of Medical Sciences,Poznan,Poland.
authors: J
authors: J
authors: Pawlak
authors: 1Psychiatric Genetics Unit,Department of Psychiatry,Poznan University of Medical Sciences,Poznan,Poland.
authors: M
authors: M
authors: Dmitrzak-Węglarz
authors: 1Psychiatric Genetics Unit,Department of Psychiatry,Poznan University of Medical Sciences,Poznan,Poland.
authors: M
authors: M
authors: Maciukiewicz
authors: 1Psychiatric Genetics Unit,Department of Psychiatry,Poznan University of Medical Sciences,Poznan,Poland.
authors: P
authors: P
authors: Kapelski
authors: 1Psychiatric Genetics Unit,Department of Psychiatry,Poznan University of Medical Sciences,Poznan,Poland.
authors: P
authors: P
authors: Czerski
authors: 1Psychiatric Genetics Unit,Department of Psychiatry,Poznan University of Medical Sciences,Poznan,Poland.
authors: A
authors: A
authors: Leszczyńska-Rodziewicz
authors: 1Psychiatric Genetics Unit,Department of Psychiatry,Poznan University of Medical Sciences,Poznan,Poland.
authors: D
authors: D
authors: Zaremba
authors: 1Psychiatric Genetics Unit,Department of Psychiatry,Poznan University of Medical Sciences,Poznan,Poland.
authors: J
authors: J
authors: Hauser
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001714:Bipolar Disorder / Q000235:genetics* / Q000523:psychology*; D058068:Endophenotypes; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D010551:Personality / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D011569:Psychiatric Status Rating Scales; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics; D013405:Suicide; D014365:Tryptophan Hydroxylase / Q000235:genetics; D055815:Young Adult
chemical_list: C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins; C497467:TPH1 protein, human; D014365:Tryptophan Hydroxylase
keywords: personality; serotonergic genes; suicide