title: Post-traumatic amnesia and the nature of post-traumatic stress disorder after mild traumatic brain injury.
abstract: The prevalence and nature of post-traumatic stress disorder (PTSD) following mild traumatic brain injury (MTBI) is controversial because of the apparent paradox of suffering PTSD with impaired memory for the traumatic event. In this study, 1167 survivors of traumatic injury (MTBI: 459, No TBI: 708) were assessed for PTSD symptoms and post-traumatic amnesia during hospitalization, and were subsequently assessed for PTSD 3 months later (N = 920). At the follow-up assessment, 90 (9.4%) patients met criteria for PTSD (MTBI: 50, 11.8%; No-TBI: 40, 7.5%); MTBI patients were more likely to develop PTSD than no-TBI patients, after controlling for injury severity (adjusted odds ratio: 1.86; 95% confidence interval, 1.78-2.94). Longer post-traumatic amnesia was associated with less severe intrusive memories at the acute assessment. These findings indicate that PTSD may be more likely following MTBI, however, longer post-traumatic amnesia appears to be protective against selected re-experiencing symptoms.
authors.affiliation: School of Psychology, University of New South Wales, Sydney, New South Wales, Australia. r.bryant@unsw.edu.au
authors.forename: Richard A
authors.initials: RA
authors.lastname: Bryant
authors.forename: Mark
authors.initials: M
authors.lastname: Creamer
authors.forename: Meaghan
authors.initials: M
authors.lastname: O'Donnell
authors.forename: Derrick
authors.initials: D
authors.lastname: Silove
authors.forename: C Richard
authors.initials: CR
authors.lastname: Clark
authors.forename: Alexander C
authors.initials: AC
authors.lastname: McFarlane
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000647:Amnesia / Q000209:etiology*; D000704:Analysis of Variance; D001930:Brain Injuries / Q000150:complications*; D016000:Cluster Analysis; D005260:Female; D005500:Follow-Up Studies; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D013223:Statistics as Topic; D013313:Stress Disorders, Post-Traumatic / Q000209:etiology*; D015599:Trauma Severity Indices; D055815:Young Adult