Background: Evidence 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. Methods: We 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. Results: When 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. Conclusion: The association between childhood mTBI and subsequent psychiatric problems and service use may be largely explained by pre-existing mental health problems.  

The authors have declared no competing interest.

GR PhD funded by the Medical Research Council

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

Approval for the current study was granted by the University College London Ethics Committee (Ref: CEHP/2023/593).

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

Data used in the preparation of this article were obtained from the Adolescent Brain Cognitive DevelopmentSM (ABCD) Study (https://abcdstudy.org), held in the NIMH Data Archive (NDA). The full code for the analysis is available in full in an online archive: https://github.com/GraceRevill/pTBI-neuropsychiatric-outcomes

https://abcdstudy.org

https://github.com/GraceRevill/pTBI-neuropsychiatric-outcomes