title: Effects of psychotherapy on DNA strand break accumulation originating from traumatic stress.
abstract: BACKGROUND
  Previous research reveals an association between traumatic stress and an increased risk for numerous diseases, including cancer. At the molecular level, stress may increase carcinogenesis via increased DNA damage and impaired DNA repair mechanisms. We assessed DNA breakage in peripheral blood mononuclear cells from individuals with post-traumatic stress disorder (PTSD) and measured the cellular capacity to repair single-strand breaks after exposure to ionizing X-radiation. We also investigated the effect of psychotherapy on both DNA breakage and DNA repair.
  
  
  METHODS
  In a first study we investigated DNA breakage and repair in 34 individuals with PTSD and 31 controls. Controls were subdivided into 11 trauma-exposed subjects and 20 individuals without trauma exposure. In a second study, we analysed the effect of psychotherapy (Narrative Exposure Therapy) on DNA breakage and repair. Thirty-eight individuals with PTSD were randomly assigned to either a treatment or a waitlist control condition. Follow-up was performed 4 months and 1 year after therapy.
  
  
  RESULTS
  In study 1 we found higher levels of basal DNA breakage in individuals with PTSD and trauma-exposed subjects than in controls, indicating that traumatic stress is associated with DNA breakage. However, single-strand break repair was unimpaired in individuals with PTSD. In study 2, we found that psychotherapy reversed not only PTSD symptoms, but also DNA strand break accumulation.
  
  
  CONCLUSIONS
  Our results show - for the first time in vivo - an association between traumatic stress and DNA breakage; they also demonstrate changes at the molecular level, i.e., the integrity of DNA, after psychotherapeutic interventions.
authors.affiliation: Center of Excellence for Psychotraumatology, Clinical Psychology and Neuropsychology, University of Konstanz, Konstanz, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Morath
authors.forename: Maria
authors.initials: M
authors.lastname: Moreno-Villanueva
authors.forename: Gilava
authors.initials: G
authors.lastname: Hamuni
authors.forename: Stephan
authors.initials: S
authors.lastname: Kolassa
authors.forename: Martina
authors.initials: M
authors.lastname: Ruf-Leuschner
authors.forename: Maggie
authors.initials: M
authors.lastname: Schauer
authors.forename: Thomas
authors.initials: T
authors.lastname: Elbert
authors.forename: Alexander
authors.initials: A
authors.lastname: Bürkle
authors.forename: Iris-Tatjana
authors.initials: IT
authors.lastname: Kolassa
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D053960:DNA Breaks; D004260:DNA Repair; D005260:Female; D006801:Humans; D007171:Implosive Therapy; D008297:Male; D008875:Middle Aged; D062525:Narrative Therapy; D013313:Stress Disorders, Post-Traumatic / Q000150:complications* / Q000235:genetics / Q000628:therapy; D013315:Stress, Psychological / Q000150:complications / Q000235:genetics / Q000628:therapy; D055815:Young Adult