INTRODUCTION. Research indicates that sex may moderate concussion recovery, with females appearing to experience poorer outcomes than males. It has been hypothesized (hormonal withdrawal hypothesis) that greater withdrawal of sex hormones in women leads to poorer outcomes. Based on this hypothesis, female athletes taking hormonal contraception should exhibit better recovery profiles as their hormone levels are artificially stabilized. Accordingly, the purpose of this study was to longitudinally examine the relation between hormonal contraceptives (HC) and concussion outcomes. We hypothesized that athletes taking hormonal contraceptives would exhibit faster recovery times, less severe clinical symptoms, and better neurological status and cognitive health, than athletes not taking hormonal contraceptives. 
METHODS. During the 2014-2017 academic years, data were collected from 30 NCAA universities and military service academies as part of the Concussion Assessment, Research, and Education (CARE) Consortium. Baseline assessments were completed prior to the beginning of the sport season for all athletes. Athletes were re-assessed 24-48 hours post-concussion, and again when they were granted unrestricted return-to-play. Length of recovery was defined as days between injury and unrestricted return-to-play. Clinical symptoms were measured using the Sport Concussion Assessment Tool (SCAT) symptom checklist, mental health was measured using the Brief Symptom Inventory-18 (BSI-18), neurological status was measured using the Standardized Assessment of Concussion (SAC), and cognitive function was measured using the ImPACT computerized test battery. Females who sustained a concussion were separated into those who were (HC+; n=50) and were not (HC–; n=50) taking hormonal contraception. Participants were matched on age, sex, body mass index, sport contact level, and concussion injury characteristics.
RESULTS. No group differences in length of recovery were observed (p > .05). Analyses revealed main effects of group for concentration (SAC; p = .04), verbal memory (ImPACT; p = .03), and cognitive efficiency (ImPACT; p = .01); suggesting that across all timepoints females on hormonal contraceptives exhibited better concentration, working memory, and cognitive efficiency. No significant interaction effects were observed. 
CONCLUSIONS. The current results indicate that hormonal contraceptives do not influence recovery time or outcomes following concussion. However, our results indicate that hormonal contraception may confer a general cognitive benefit, irrespective of injury status.

The Influence of Hormonal Contraceptives on Concussion Outcomes in Collegiate Athletes: Data from the NCAA-DoD CARE Consortium