Theadom, AliceBarker-Collo, SuzanneParag, VarshaCaspi, AvshalomMoffitt, Terri EHogan, SeanRamrakha, SandhyaPoulton, Richie2026-06-292026-06-292023-06-19Journal of Head Trauma Rehabilitation, ISSN: 0885-9701 (Print); 1550-509X (Online), Lippincott, Williams & Wilkins, 39(2), E70-E82. doi: 10.1097/HTR.00000000000008750885-97011550-509Xhttp://hdl.handle.net/10292/21523OBJECTIVE: To determine whether differences exist in mid-adulthood cognitive functioning in people with and without history of mild traumatic brain injury (mTBI). SETTING: Community-based study. PARTICIPANTS: People born between April 1, 1972, and March 31, 1973, recruited into the Dunedin Multidisciplinary Health and Development Longitudinal Study, who completed neuropsychological assessments in mid-adulthood. Participants who had experienced a moderate or severe TBI or mTBI in the past 12 months were excluded. DESIGN: Longitudinal, prospective, observational study. MAIN MEASURES: Data were collected on sociodemographic characteristics, medical history, childhood cognition (between 7 and 11 years), and alcohol and substance dependence (from 21 years of age). mTBI history was determined from accident and medical records (from birth to 45 years of age). Participants were classified as having 1 mTBI and more in their lifetime or no mTBI. The Wechsler Adult Intelligence Scale (WAIS-IV) and Trail Making Tests A and B (between 38 and 45 years of age) were used to assess cognitive functioning. T tests and effect sizes were used to identify any differences on cognitive functioning domains between the mTBI and no mTBI groups. Regression models explored the relative contribution of number of mTBIs and age of first mTBI and sociodemographic/lifestyle variables on cognitive functioning. RESULTS: Of the 885 participants, 518 (58.5%) had experienced at least 1 mTBI over their lifetime, with a mean number of 2.5 mTBIs. The mTBI group had significantly slower processing speed (P < .01, d = 0.23) in mid-adulthood than the no TBI controls, with a medium effect size. However, the relationship no longer remained significant after controlling for childhood cognition, sociodemographic and lifestyle factors. No significant differences were observed for overall intelligence, verbal comprehension, perceptual reasoning, working memory, attention, or cognitive flexibility. Childhood cognition was not linked to likelihood of sustaining mTBI later in life. CONCLUSION: mTBI histories in the general population were not associated with lower cognitive functioning in mid-adulthood once sociodemographic and lifestyle factors were taken into account.Copyright © 2024 The Authors. Published by Wolters Kluwer Health, Inc. Note: This article is available under the Creative Commons CC-BY-NC-ND license and permits non-commercial use of the work as published, without adaptation or alteration provided the work is fully attributed.5201 Applied and Developmental Psychology5203 Clinical and Health Psychology4206 Public Health42 Health Sciences52 PsychologyTraumatic Brain Injury (TBI)Brain DisordersNeurosciencesPediatric Research InitiativeClinical ResearchBehavioral and Social ScienceBasic Behavioral and Social SciencePhysical Injury - Accidents and Adverse EffectsSocial Determinants of HealthTraumatic Head and Spine Injury2.4 Surveillance and distributionMental health3 Good Health and Well Being11 Medical and Health Sciences17 Psychology and Cognitive SciencesRehabilitation32 Biomedical and clinical sciences42 Health sciences52 PsychologyAdultHumansChildBrain ConcussionProspective StudiesLongitudinal StudiesCohort StudiesCognitionNeuropsychological TestsHumansBrain ConcussionCohort StudiesLongitudinal StudiesProspective StudiesCognitionNeuropsychological TestsAdultChildAdultHumansChildBrain ConcussionProspective StudiesLongitudinal StudiesCohort StudiesCognitionNeuropsychological TestsJournal ArticleOpenAccess10.1097/HTR.0000000000000875