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

JAMA Netw Open. 2021 Dec 1;4(12):e2140359. doi: 10.1001/jamanetworkopen.2021.40359.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Athletic Injuries / complications*
  • Attention Deficit Disorder with Hyperactivity / etiology*
  • Brain Concussion / complications*
  • Child
  • Cognition
  • Cohort Studies
  • Football / injuries*
  • Humans
  • Male
  • Prospective Studies