Paediatric traumatic brain injury and attention-deficit/hyperactivity disorder medication in Finland: a nationwide register-based cohort study.

Background: The association between paediatric traumatic brain injury (pTBI) and post-traumatic attention-deficit/hyperactivity disorder (ADHD) medication usage remains understudied subject.

Objective: We aimed to evaluate the association between pTBI and subsequent ADHD medication.

Methods: A nationwide retrospective cohort study in Finland from 1998 to 2018 included 66 594 patients with pTBI and 61 412 references with distal extremity fractures. ADHD medication data were obtained from the Finnish Social Insurance Institution. The primary outcome was post-traumatic pediatric ADHD medication. A 1-year washout period was applied, and follow-up started 1 year post-pTBI.

Findings: Kaplan-Meier analyses showed higher ADHD medication usage in patients with pTBI, especially post-operatively. Both sex groups exhibited elevated rates compared with the reference group. Over 10 years, cumulative incidence rates were 3.89% (pTBI) vs 1.90% (reference). HR for pTBI was 1.89 (95% CI 1.70 to 2.10) after 4 years and 6.31 (95% CI 2.80 to 14.20) for the operative group after the initial follow-up year. After 10 years, cumulative incidence in females increased to 2.14% (pTBI) vs 1.07% (reference), and in males, to 5.02% (pTBI) vs 2.35% (reference). HR for pTBI was 2.01 (95% CI 1.72 to 2.35) in females and 2.23 (95% CI 2.04 to 2.45) in males over 1-20 years.

Conclusions: A substantial association between pTBI and post-traumatic ADHD medication was evidenced over a 20-year follow-up period.

Clinical implications: These results stress the need for preventive measures for pTBI and highlight the potential impact of long-term post-traumatic monitoring and psychoeducation.