title: Longitudinal changes in serum brain-derived neurotrophic factor in accident survivors with posttraumatic stress disorder.
abstract: BACKGROUND
  This prospective cohort study investigated the serum levels of brain-derived neurotrophic factor (BDNF), which mediates synaptic plasticity crucial for fear memory extinction, in patients severely injured in motor vehicle accidents (MVAs).
  
  
  METHODS
  A nested, case-controlled study was conducted with 103 MVA survivors: 8 medication-naïve patients who met the criteria for full diagnosis of posttraumatic stress disorder (PTSD) at 6 months after MVA, 10 medication-naïve patients with partial PTSD and 85 patients with no PTSD. PTSD was evaluated by the Clinician-Administered PTSD Scale (CAPS). Serum BDNF levels were measured shortly after the MVA (baseline) and at 6-month follow-up.
  
  
  RESULTS
  Posttrauma serum BDNF levels differed between the 3 groups after controlling for age and sex (F = 3.41, p = 0.04), with unexpectedly higher serum BDNF levels seen in the full-PTSD group compared with the no-PTSD group. Additional analysis of patients with serum samples taken at baseline and at 6 months revealed the full-PTSD group had significantly higher serum BDNF levels over the 6 months than the no-PTSD group after controlling for age and sex (F = 6.44, p < 0.01). A positive correlation was seen between changes in serum BDNF levels over 6 months and the CAPS score at 6 months (r = 0.26, p = 0.014).
  
  
  CONCLUSIONS
  The findings of this study, the first to report longitudinal serum BDNF levels in MVA survivors, suggest that elevated serum BDNF levels could be a biomarker of PTSD after a traumatic event.
authors.affiliation: Department of Clinical Epidemiology, Translational Medical Center, National Center of Neurology and Psychiatry, Tokyo, Japan. yutaka@ncnp.go.jp
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Matsuoka
authors.forename: Daisuke
authors.initials: D
authors.lastname: Nishi
authors.forename: Hiroko
authors.initials: H
authors.lastname: Noguchi
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Kim
authors.forename: Kenji
authors.initials: K
authors.lastname: Hashimoto
mesh_terms: D000063:Accidents, Traffic / Q000523:psychology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D013313:Stress Disorders, Post-Traumatic / Q000097:blood* / Q000175:diagnosis; D017741:Survivors / Q000523:psychology*
chemical_list: D015415:Biomarkers; D019208:Brain-Derived Neurotrophic Factor