The Influence of ADHD on Concussion in NCAA College Athletes

Evidence suggests attention deficit/hyperactivity disorder (ADHD) may be associated with an increased incidence of concussion; however, no study has cross-sectionally (Aim 1) and longitudinally (Aim 2) assessed the associations of ADHD with concussion. Additionally, there is reason to expect cognitive alterations following concussion in athletes with ADHD. Further, there is currently no study that has evaluated the influence of common medications often taken to mitigate some symptoms of ADHD, such as methylphenidate and amphetamines. Therefore, we sought to longitudinally assess cognitive profiles (Aim 3) of athletes with ADHD taking medication (ADHD+Rx) and not taking medication (ADHD_uRx) at baseline, 24-48 hours post-injury, and at unrestricted return-to-play (uRTP).2014-2017 data from the NCAA-DOD Grand Alliance: Concussion Assessment, Research, and Education (CARE) Consortium were used to evaluate the likelihood of concussion for athletes with ADHD (n=1513), and relative to controls (n=31,122). Odds of concussion history prior to enrollment, and relative risk of incurring a concussion following enrollment were calculated for all groups. Additionally, odds and risk were calculated within and between sexes, as well as for NCAA contact level (i.e., contact, limited-contact, and non-contact) to provide further information useful for interpreting the findings. For Aim 3, our analysis included 140 controls double-matched to 35 ADHD+Rx and 35 ADHD_uRx. These concussed athletes were reassessed at multiple time points across recovery: within 6-hours of injury, 24-48 hours post-injury, and time of unrestricted return-to-play. We observed that both male and female athletes with self-reported diagnosis of ADHD had significantly greater odds of single and multiple concussions than controls (Aim 1). we prospectively observed that all athletes with ADHD had greater risk for incurring a concussion during the study period (Aim 2). Additionally, we observed that unmedicated athletes with ADHD performed worse on measures of impulse control, reaction time, and visual motor speed at baseline (Aim 3). At 24-48 hours post-injury unmedicated ADHD group performed worse than controls, but not the medicated ADHD group, for reaction time, visual memory, and cognitive efficiency. However, the unmedicated ADHD group performed worse than both medicated ADHD and controls for visual motor speed. Interestingly, the medicated ADHD group performed worse than controls, but not unmedicated ADHD, for impulse control, suggesting a reemergence of self-regulatory difficulties for medicated ADHD. Finally, at uRTP the unmedicated ADHD group performed worse for reaction time than both controls and medicated ADHD. Controls also reported fewer total symptoms than either medicated or unmedicated. Additionally, the unmedicated ADHD group performed worse than controls, but not medicated ADHD for verbal memory, visual memory, and visual motor speed