title: The risk of posttraumatic stress disorder after trauma depends on traumatic load and the catechol-o-methyltransferase Val(158)Met polymorphism.
abstract: BACKGROUND
  The risk for posttraumatic stress disorder (PTSD) depends on the number of traumatic event types experienced in a dose-response relationship, but genetic factors are known to also influence the risk of PTSD. The catechol-O-methyltransferase (COMT) Val158Met polymorphism has been found to affect fear extinction and might play a role in the etiology of anxiety disorders.
  
  
  METHODS
  Traumatic load and lifetime and current diagnosis of PTSD and COMT genotype were assessed in a sample of 424 survivors of the Rwandan Genocide living in the Nakivale refugee camp in southwestern Uganda.
  
  
  RESULTS
  Higher numbers of different lifetime traumatic event types led to a higher prevalence of lifetime PTSD in a dose-response relationship. However, this effect was modulated by the COMT genotype: whereas Val allele carriers showed the typical dose-response relationship, Met/Met homozygotes exhibited a high risk for PTSD independently of the severity of traumatic load.
  
  
  CONCLUSIONS
  The present findings indicate a gene-environment interaction between the human COMT Val158Met polymorphism and the number of traumatic event types experienced in the risk of developing PTSD.
authors: University of Konstanz, Germany. Iris.Kolassa@uni-konstanz.de
authors: Iris-Tatjana
authors: IT
authors: Kolassa
authors: Stephan
authors: S
authors: Kolassa
authors: Verena
authors: V
authors: Ertl
authors: Andreas
authors: A
authors: Papassotiropoulos
authors: Dominique J-F
authors: DJ
authors: De Quervain
mesh_terms: D000293:Adolescent; D000328:Adult; D000349:Africa; D000368:Aged; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D016009:Chi-Square Distribution; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008016:Life Change Events; D008297:Male; D008715:Methionine / Q000235:genetics*; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D011336:Probability; D012307:Risk Factors; D013313:Stress Disorders, Post-Traumatic / Q000235:genetics*; D014633:Valine / Q000235:genetics*; D055815:Young Adult
chemical_list: D008715:Methionine; D002394:Catechol O-Methyltransferase; D014633:Valine