Paediatric Traumatic Brain Injury and Long-Term Antidepressant Use: A Nationwide Register-Based Cohort Study

Aim: The association between paediatric traumatic brain injury (pTBI) and post-traumatic antidepressant medication usage remains an understudied subject. Methods: A nationwide Finnish retrospective cohort study (1998–2018) included 71 969 pTBI patients and 64 856 orthopaedic references. Antidepressant medication data were sourced from the Finnish Social Insurance Institution. The primary outcome was post-traumatic paediatric antidepressant use. Results: The study included 136 825 patients. Kaplan–Meier analyses showed higher antidepressant use in pTBI patients, especially after 5 years and following surgery. The cumulative incidence rate (CIR) after 1 year was 0.73% (pTBI) versus 0.34% (references), increasing to 26.95% versus 25.51% after 20 years. Cox regression showed a higher long-term risk in pTBI patients (HR 1.31, up to 9 years). Operatively treated pTBI had an HR of 4.45 after 2 years. Among females, HR was 2.60 after 1 year, while in males, HR was 1.54. Conclusions: The risk of antidepressant use following pTBI is notably higher after the first year, for both sexes and among patients who undergo operative treatment for pTBI. This elevated risk persists for 9 years but then declines.