Exposure to Head Impacts and Cognitive and Behavioral Outcomes in Youth Tackle Football Players Across 4 Seasons

Key Points Question Are repetitive head impacts in youth tackle football across 4 years of play associated with cognitive and behavioral difficulties? Findings In this cohort study including 70 male participants aged 9 to 12 years, few associations were found between cumulative head impacts and cognitive and behavioral outcomes, and no associations were seen consistently or became more prominent over the years. Meaning Because head impacts were not associated with measured outcomes, these findings suggest that other factors, including premorbid medical conditions, should be further explored.
This cohort study examines the association between cognitive and behavioral outcomes and head impacts measured in youth tackle football players over 4 seasons of play.
Importance Repetitive head impacts have been posited to contribute to neurocognitive and behavioral difficulties in contact sport athletes. Objective To identify associations between cognitive and behavioral outcomes and head impacts measured in youth tackle football players over 4 seasons of play. Design, Setting, and Participants This prospective cohort study was conducted from July 2016 through January 2020, spanning 4 football seasons. The setting was a youth tackle football program and outpatient medical clinic. Players were recruited from 4 football teams composed of fifth and sixth graders, and all interested players who volunteered to participate were enrolled. Data analysis was performed from March 2020 to June 2021. Exposures Impacts were measured using helmet-based sensors during practices and games throughout 4 consecutive seasons of play. Impacts were summed to yield cumulative head impact gravitational force equivalents per season. Main Outcomes and Measures Ten cognitive and behavioral measures were completed before and after each football season. Results There were 70 male participants aged 9 to 12 years (mean [SD] age, 10.6 [0.64] years), with 18 completing all 4 years of the study. At the post–season 1 time point, higher cumulative impacts were associated with lower self-reported symptom burden (β = −0.6; 95% CI, −1.0 to −0.2; P = .004). After correcting for multiple comparisons, no other associations were found between impacts and outcome measures. At multiple times throughout the study, premorbid attention-deficit/hyperactivity disorder, anxiety, and depression were associated with worse cognitive or behavioral scores, whereas a premorbid headache disorder or history of concussion was less often associated with outcomes. Conclusions and Relevance In this cohort of youth tackle football players, premorbid conditions, including attention-deficit/hyperactivity disorder, anxiety, and depression, were associated with cognitive and behavioral outcomes more often than cumulative impact.