Cognitive and Neuropsychiatric Function in Former American Football Players

Repetitive head impacts (RHI) from American football have been associated with later-life cognitive and neuropsychiatric changes. Findings have been limited by small samples, focus on elite players, and lack of appropriate control groups.

To assess the association between American football participation and cognitive and neuropsychiatric function in men 40 years or older.

In this cross-sectional study, online data from male football players in the Head Impact & Trauma Surveillance Study (HITSS) were collected between March 7, 2022, and April 9, 2025. In a subanalysis, football players were matched to Brain Health Registry controls without RHI.

RHI proxies, including self-reported total years of football play, highest level of play, position, and age of first exposure.

Linear regression models with multiway cluster-robust SEs compared performance of players vs controls on computerized cognitive tests (Cambridge Automated Neuropsychological Battery Paired Associates Learning Test First Attempt Memory Score [PALFAMS] and Total Errors Adjusted [PALTEA]), subjective cognitive concerns (Everyday Cognition Scale [ECog]), and depressive symptoms (Geriatric Depression Scale 15 [GDS-15]). Multivariable linear regressions, analyses of covariance, and binary logistic regression models tested associations between RHI proxies and PALFAMS, PALTEA, ECog, GDS-15, and additional neuropsychiatric (Behavior Rating Inventory of Executive Function-Adult [BRIEF-A] Behavioral Regulation Index [BRI]) and cognitive (BRIEF-A Meta-Cognition Index [MI]) measures. Models were adjusted for age, race, educational level, and vascular risk.

The study sample included 3970 male former American football players (mean [SD] age, 55.93 [10.00] years) enrolled in HITSS. Two substudies were performed: (1) all 3970 football players and (2) 943 players and controls (mean [SD] age, 58.46 [10.37] years), including 661 football players and 282 Brain Health Registry controls. Overall, all study participants were highly educated (561 [85%] had a ≥4-year degree). Compared with controls, players had worse scores on PALFAMS (B = -0.64; 95% CI, -1.23 to 0.05; β = -0.15; P = .03), PALTEA (B = 0.31; 95% CI, 0.07-0.54; β = 0.18; P = .01), ECog (B = 0.11; 95% CI, 0.07-0.15; β = 0.38; P < .001), and GDS-15 (B = 0.62; 95% CI, 0.39-0.86; β = 0.37; P < .001). Among the 3970 total players (mean [SD] years of education, 16.11 [2.20]), professional players had worse scores than college and high school or youth players. Years of play was associated with higher ECog (B = 0.006; 95% CI, 0.003-0.009; adjusted P < .001), MI (B = 0.17; 95% CI, 0.02-0.32; adjusted P = .04), BRI (B = 0.27; 95% CI, 0.16-0.37; adjusted P < .001), GDS-15 (B = 0.03; 95% CI, 0.009-0.04; adjusted P = .003), and PALTEA (B = 0.03; 95% CI, 0.004-0.06; adjusted P = .04) scores.

In this cross-sectional study of former American football players, prior American football participation was associated with worse later-life cognitive and neuropsychiatric function. These findings support a dose-response association with years and level of play, providing context to help clinicians and researchers assess the risk of symptoms among former players.