Mild Traumatic Brain Injuries and Risk for Affective and Behavioral Disorders.

Objectives: Recent studies document an association between mild traumatic brain injuries (mTBIs) in children and postinjury psychiatric disorders. However. these studies were subject to limitations in the design, lack of long-term follow-up, and poorly defined psychiatric outcomes. This study determines the incidence and relative risk of postinjury new affective and behavior disorders 4 years after mTBIs.

Methods: A cohort study of mTBI cases and matched comparisons within an integrated health care system. The mTBI group included patients ≤17 years of age, diagnosed with mTBI from 2000 to 2014 (N = 18 917). Comparisons included 2 unexposed patients (N = 37 834) per each mTBI-exposed patient, randomly selected and matched for age, sex, race/ethnicity, and date of medical visit (reference date to mTBI injury). Outcomes included a diagnosis of affective or behavioral disorders in the 4 years after mTBI or the reference date.

Results: Adjusted risks for affective disorders were significantly higher across the first 3 years after injury for the mTBI group, especially during the second year, with a 34% increase in risk. Adjusted risks for behavioral disorders were significant at years 2 and 4, with up to a 37% increase in risk. The age group with the highest risk for postinjury affective and behavioral disorders was 10- to 13-year-old patients.

Conclusions: Sustaining an mTBI significantly increased the risks of having a new affective or behavioral disorder up to 4 years after injury. Initial and ongoing screening for affective and behavior disorders following an mTBI can identify persistent conditions that may pose barriers to recovery.