Association between Paediatric Mild Traumatic Brain Injury and Two-Year Psychiatric Outcomes Largely Explained by Pre-Existing Mental Health Problems

Abstract

AbstractBackgroundEvidence that mild traumatic brain injury (mTBI) causes psychiatric problems in children has been mixed. Investigating this issue has been difficult due to the lack of representative longitudinal data on child mTBI that includes adequate measures of subsequent mental health symptoms and service use in young people.MethodsWe used data from the ABCD longitudinal cohort study to examine the association between mTBI and psychiatric diagnoses, symptoms, and psychiatric service use in over 11,000 children aged 9-10 at i) baseline, and ii) with new cases of mTBI since baseline and psychiatric outcomes and service use at two-year follow-up. We also compared mTBI cases to a comparison group of participants with orthopaedic injury but without mTBI. Mixed-effects models were used and adjusted for demographic and social covariates, with missing data imputed using random forest multiple imputation. To account for baseline mental health outcomes, we used propensity-score matching to identify a comparison sample matched on potential confounding variables and baseline outcome measures.ResultsWhen examined without adjustment for baseline mental health, both lifetime mTBI at baseline, and new occurrence of mTBI at two-year follow-up, were reliably associated with an increased risk of DSM-5 anxiety and behavioural disorders, mental health symptom scores measured psychometrically, and increased psychiatric service use. These associations were not present, or occasionally only minimally present, in the orthopaedic injury comparison group. However, controlling for baseline mental health using propensity-score matching resulted in no association between new incidence mTBI and psychiatric symptoms, diagnoses and service use, with the exception of parent-reported anxiety and conduct symptom scores in supplementary analyses.ConclusionThe association between childhood mTBI and subsequent psychiatric problems and service use may be largely explained by pre-existing mental health problems.