Objective This study investigated the longitudinal course of depressive symptom severity over 19 years in former American football players and the influence of concussion history, contact sport participation and physical function on observed trajectories.
Methods Former American football players completed a general health questionnaire involving demographic information, medical/psychiatric history, concussion/football history and validated measures of depression and physical function at three time points (2001, 2010 and 2019). Parallel process latent growth curve modelling tested associations between concussion history, years of football participation, and overall and change in physical function on the overall level and trajectory of depressive symptoms.
Results Among the 333 participants (mean(SD) age, 48.95 (9.37) at enrolment), there was a statistically significant, but small increase in depressive symptom severity from 2001 (48.34 (7.75)) to 2019 (49.77 (9.52)), slope=0.079 (SE=0.11), p=0.007. Those with greater concussion history endorsed greater overall depressive symptom severity, B=1.38 (SE=0.33), p<0.001. Concussion history, B<0.001 (SE=0.02), p=0.997 and years of participation, B<0.001 (SE=0.01), p=0.980, were not associated with rate of change (slope factor) over 19 years. Greater decline in physical function, B=−0.71 (SE=0.16), p<0.001, was predictive of a faster growth rate (ie, steeper increase) of depression symptom endorsement over time.
Conclusions Concussion history, not years of participation, was associated with greater depressive symptom severity. Neither factor was predictive of changes over a 19-year period. Decline in physical function was a significant predictor of a steeper trajectory of increased depressive symptoms, independent of concussion effects. This represents one viable target for preventative intervention to mitigate long-term neuropsychiatric difficulties associated with concussion across subsequent decades of life.
- traumatic brain injury
Data availability statement
Data are available on reasonable request. The data used as part of this study that support the reported findings are available from the corresponding author (BLB), on reasonable request.
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Contributors BLB: designed and conceptualised the study; major role in acquisition of the data; analysed data; drafted and revised the manuscript for intellectual content. As the guarantor, he accepts full responsibility for the finished work and/or the conduct of the study, had access to the data, and controlled the decision to publish. SW: major role in acquisition of the data; analysed data; revised the manuscript for intellectual content. ZK: major role in acquisition of the data; analysed data; revised the manuscript for intellectual content. RM: designed and conceptualised study; analysed data; drafted the manuscript for intellectual content. AC: revised the manuscript for intellectual content. JDD: revised the manuscript for intellectual content. RE: major role in acquisition of the data; revised the manuscript for intellectual content. KMG: major role in acquisition of the data; analysed data; revised the manuscript for intellectual content. WM: major role in acquisition of the data; analysed data; revised the manuscript for intellectual content. MM: designed and conceptualised study; major role in acquisition of the data; analysed data; revised the manuscript for intellectual content.
Funding This study (NFL-LONG) was funded by the National Football League (NFL) with support from the National Institute on Aging (BLB-Award Number K23 AG073528).
Competing interests BLB acknowledges support from the National Institute of Neurological Disorders and Stroke (Award Number L30NS113158-02) and National Institute on Aging (Award Number K23 AG073528).
ZYK reports grants from National Institutes of Health; grants from Centers for Disease Control and Prevention; and grants from National Football League. AC discloses funding from the National Collegiate Athletic Association. RM reports grants from U.S. Department of Defense; grants from NFL Foundation; and grants from National Institute of Neurological Disorders and Stroke. RE is a paid consultant for the NHL and co-chair of the NHL/NHLPA Concussion Subcommittee. He is also a paid consultant for Major League Soccer and Princeton University Athletic Medicine and occasionally provides expert testimony in matters related to MTBI and sports concussion. WM receives royalties from (1) ABC-Clio publishing for the sale of his books, Kids, Sports and Concussion: A guide for coaches and parents, and Concussions; (2) Springer International for the book Head and Neck Injuries in Young Athlete and (3) Wolters Kluwer for working as an author for UpToDate. His research is funded, in part, by philanthropic support from the National Hockey League Alumni Association through the Corey C. Griffin Pro-Am Tournament and a grant from the National Football League.Dr Guskiewicz reports compensation from National Collegiate Athletic Association for other services and grants from Boston Children's Hospital (sub-award from the National Football League). MM acknowledges researching funding from the NIH, US Dept. of Defense, CDC, NCAA and NFL to the Medical College of Wisconsin.
Provenance and peer review Not commissioned; externally peer reviewed.