title: Neuropsychological outcome and its correlates in the first year after adult mild traumatic brain injury: A population-based New Zealand study.
abstract: OBJECTIVE
  The relationship between moderate/severe traumatic brain injury (TBI) and cognitive deficits is well known. The nature, duration and predictors of cognitive difficulties post-mild TBI remain unclear. This study examined cognitive, mood and post-concussion outcomes of mild TBI over 1-year post-injury.
  
  
  METHODS
  Adults (>15 years) with mild TBI (n = 260) completed neuropsychological (CNS-Vital Signs, Behavioural Dyscontrol Scale), mood (Hospital Anxiety Depression Scale) and behavioural assessments (Cognitive Failures Questionnaire, Rivermead Post-Concussion Questionnaire) at baseline, 1-, 6- and 12-months post-injury.
  
  
  RESULTS
  Over the 12-months post-injury self-reported cognition (p = 0.027), post-concussion symptoms (p < 0.001), depression (p < 0.001), anxiety (p < 0.001) and dyscontrol (p = 0.025) improved significantly. Assessments of memory, processing speed, executive function, psychomotor speed/reaction time, complex attention and flexibility also improved significantly. At baseline >20% of individuals produced very low scores on executive ability, complex attention and cognitive flexibility. At 1- and 6-month follow-ups >20% of participants were very low for complex attention, with 16.3% remaining so at 12-months. Executive abilities and speed were related to post-concussion symptoms, mood and self-reported cognition at 12-months.
  
  
  CONCLUSIONS
  Whilst significant improvements were noted across measures over time, a significant proportion of individuals still perform poorly on neuropsychological measures 12-months after mild TBI; and these were linked to post-concussion symptoms, mood and self-reported cognitive outcomes. This implies a longer trajectory for recovery than has previously been suggested, which has implications for provision of assessment and rehabilitation services for more extended periods.
authors.affiliation: a School of Psychology, Faculty of Sciences, University of Auckland , New Zealand .
authors.forename: Suzanne
authors.initials: S
authors.lastname: Barker-Collo
authors.affiliation: b National Institute for Stroke and Applied Neuroscience, School of Rehabilitation and Occupation Studies, Auckland University of Technology , Auckland , New Zealand .
authors.forename: Kelly
authors.initials: K
authors.lastname: Jones
authors.affiliation: b National Institute for Stroke and Applied Neuroscience, School of Rehabilitation and Occupation Studies, Auckland University of Technology , Auckland , New Zealand .
authors.forename: Alice
authors.initials: A
authors.lastname: Theadom
authors.affiliation: c School of Psychology, Faculty of Arts and Social Sciences, University of Waikato , Hamilton , New Zealand .
authors.forename: Nicola
authors.initials: N
authors.lastname: Starkey
authors.affiliation: d Department of Primary Health Care and General Practice , University of Otago , Wellington , New Zealand .
authors.forename: Anthony
authors.initials: A
authors.lastname: Dowell
authors.affiliation: e Person Centered Research Centre, Health and Rehabilitation Research Institute, Auckland University of Technology , Auckland , New Zealand .
authors.forename: Kathryn
authors.initials: K
authors.lastname: McPherson
authors.affiliation: f School of Population Health, Faculty of Medical & Health Sciences, University of Auckland , New Zealand , and.
authors.forename: Shanthi
authors.initials: S
authors.lastname: Ameratunga
authors.affiliation: g School of Public Health & Psychosocial Studies, Auckland University of Technology , Auckland , New Zealand.
authors.forename: Margaret
authors.initials: M
authors.lastname: Dudley
authors.affiliation: b National Institute for Stroke and Applied Neuroscience, School of Rehabilitation and Occupation Studies, Auckland University of Technology , Auckland , New Zealand .
authors.forename: Braden
authors.initials: B
authors.lastname: Te Ao
authors.affiliation: b National Institute for Stroke and Applied Neuroscience, School of Rehabilitation and Occupation Studies, Auckland University of Technology , Auckland , New Zealand .
authors.forename: Valery
authors.initials: V
authors.lastname: Feigin
mesh_terms: D000293:Adolescent; D000328:Adult; D000339:Affect; D000368:Aged; D000369:Aged, 80 and over; D001288:Attention; D001924:Brain Concussion / Q000175:diagnosis / Q000523:psychology*; D001930:Brain Injuries / Q000523:psychology*; D003072:Cognition Disorders / Q000523:psychology; D056344:Executive Function; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory; D008875:Middle Aged; D009520:New Zealand; D038223:Post-Concussion Syndrome / Q000523:psychology; D057566:Self Report; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Cognition; concussion; mild traumatic brain injury; mood; post-concussion