Neurodevelopmental disorders (NDs) are a class of comorbidities gaining considerable attention by concussion researchers. Accumulating evidence suggests NDs may be associated with increased history and risk for concussion. However, no studies have compared the differential likelihood of incurring a concussion within ND sub-types: learning disability (LD), attention deficit/hyperactivity disorder (ADHD), and comorbid (LD+ADHD).
Data from the NCAA-DOD Grand Alliance: Concussion Awareness, Research, and Education (CARE) Consortium were used to evaluate the likelihood of incurring a concussion for athletes with LD (n=429), ADHD (n=1513), and LD+ADHD (n=323), relative to controls (n=31130). All groups were evaluated retrospectively (odds of concussion history) and prospectively (risk of incurring concussion within a season).

The odds ratio of concussion history at baseline for athletes with LD was 1.61 (95% CI, 1.31 to 1.97) and relative risk of LD for incurring a concussion within a season was 1.22 (95% CI, .88 to 1.69). The odds ratio of concussion history at baseline for athletes with ADHD was 1.92 (95% CI, 1.72 to 2.14) and relative risk of ADHD for incurring a concussion within a season was 1.51 (95% CI, 1.29 to 1.77). The odds ratio of concussion history at baseline for athletes with LD+ADHD was 1.85 (95% CI, 1.47 to 2.33) and relative risk of LD+ADHD for incurring a concussion within a season was 2.62 (95% CI, 2.05 to 3.35) 
Overall, NDs are associated with increased odds and relative risk of incurring a concussion. Further, athletes with comorbid LD+ADHD appear to have the greatest risk of incurring a concussion. Given the prevalence of NDs, additional steps should be taken to prevent concussions in these athletes. The authors acknowledge that CARE does not capture adequate control for athletic exposures like most sports epidemiology studies. Individuals with neurodevelopmental disorders could have similar risk once exposure is controlled for.

Neurodevelopmental Disorders and Risk of Concussion: Findings from the NCAA-DOD Concussion Consortium