title: The relationship between urinary melatonin metabolite excretion and posttraumatic symptoms following traumatic injury.
abstract: BACKGROUND
  Associations between 24-hour urinary 6-sulphatoxy melatonin excretion and symptoms of posttraumatic stress disorder were assessed 2 days, 1 month and 6 months after traumatic injury requiring hospitalisation.
  
  
  METHODS
  Forty-eight participants were recruited following an admission to hospital for an acute traumatic injury. They completed assessments 48h after the accident, 1 month and 6 months later. A 24-hour urine collection was initiated the morning before questionnaires were administered. PTSD symptoms and caseness was determined using the Impact of Event Scale (IES-R) and the Clinician Administered PTSD Scale respectively. Urinary 6-sulphatoxy melatonin was assayed by radioimmunoassay.
  
  
  RESULTS
  Mean age of participants was 34 years (SD=12.72) and 75% were males. Ten (27%) participants met the criteria for PTSD 1 month post trauma and 6 (21%) met the criteria for PTSD at 6 months. Four of the six (67%) participants with PTSD at 6 months were also positive for major depression. Significant negative correlations were found between 6-sulphatoxy melatonin excretion at day 2 and all subscales and total score of the IES-R at the six month assessment. Controlling for depression, every one unit decrease in 6-sulphatoxy melatonin excretion was associated with a 13% increase in PTSD risk at six months (OR=1.13, 95% CI 1.00-1.27). However, this association was lost when self-reported pain, gender and employment was added to the model (OR=1.11, 0.93-1.32).
  
  
  CONCLUSIONS
  This study provides preliminary data suggesting disrupted melatonin levels in the first 48h following trauma may place individuals at increased risk of PTSD.
authors.affiliation: Centre for Military and Veterans Health, School of Population Health and Clinical Practice, The University of Adelaide, Australia.
authors.forename: Alexander C
authors.initials: AC
authors.lastname: McFarlane
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Barton
authors.forename: Nancy
authors.initials: N
authors.lastname: Briggs
authors.forename: David J
authors.initials: DJ
authors.lastname: Kennaway
mesh_terms: D000063:Accidents, Traffic / Q000523:psychology; D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008550:Melatonin / Q000031:analogs & derivatives* / Q000652:urine; D008875:Middle Aged; D011446:Prospective Studies; D013021:South Australia; D013313:Stress Disorders, Post-Traumatic / Q000175:diagnosis / Q000523:psychology* / Q000652:urine*; D014947:Wounds and Injuries / Q000523:psychology* / Q000652:urine*; D055815:Young Adult
chemical_list: C054513:6-sulfatoxymelatonin; D008550:Melatonin