Trends in concussion reporting and depression across debut years in professional American-style football play

Abstract

Head injuries accrued during professional football have been associated with long term health issues. Efforts over the last 80 years to limit concussions have included rule changes, improved helmet technologies, and increased general awareness of the negative health consequences of head injury, including depression. However, few studies have evaluated whether these exposures and outcomes change over time. This work addresses this knowledge gap by evaluating the extent to which concussion symptoms and depression symptoms (measured by the PHQ-2) change by a player’s debut year. Using multivariable models, it was found that concussion scores and depressive symptoms both change over the time period of 1960-2020 in a similar way. Furthermore, since head exposure has been found to depend on position, I investigated whether changes over time were different by position. Stratification by position showed no changes in the patterns of reporting compared to one another nor patterns seen in the entire cohort, although linemen and speed positions did report higher concussion and depression scores overall, as expected. I also examined whether eras defined by rule-based changes were associated with these patterns through non-linear models for three pre-defined, rules-based eras – 1960-1976, 1977-2010, and 2011-2020. Despite the inclusion of rules-based eras, the driving forces behind these changes in reporting remained unclear. Future work is needed to establish influencers of concussion and depression reporting change if we hope to improve player safety and post-career quality of life.