Each year approximately 1.6 to 3.8 million people suffer a sports-related traumatic brain injury (Langlois, Rutland-Brown, & Wald, 2006). Concussions, a common form of mild traumatic brain injury, account for 75% of total brain injuries in the United States (Faul, Xu, Wald, & Coronado, 2010). In sports, concussions account for 1 of every 10 injuries (Marar, McIlvain, Fields, & Comstock, 2012). Overall, concussion symptoms typically remit within one to four weeks from injury (McCrea, 2007); however, conflict exists surrounding the duration of time that would be safe for a concussed student-athlete to return to functioning, both to sport and to class. According to the most recent evidence on concussion recovery and return to play statistics in a collegiate student-athlete population, an athlete, on average, will return to functioning within 16.1 days (McCrea et al., 2019). The primary role in evaluating collegiate sports-related concussions is to determine when and how a student-athlete should return to physical and cognitive activity. Concussions are known to result in a wide array of neurologic, somatic, cognitive, and behavioral deficits. The diagnosis of a concussion is determined by the athlete's presentation of symptoms; however, many of these symptoms are both subjective and ubiquitous. When athletes are concussed, they undergo a series of tests including a self-reported inventory of symptoms. Previous research has identified four distinct domains of symptoms endorsed by athletes on the Post-Concussion Symptom Scale (PCSS) consisting of cognitive, physical, affective, and sleep symptoms (Merritt & Arnett, 2014). The aim of this study is to critically examine post-concussive symptoms within a collegiate athlete sample and identify existing relationships between symptom clusters and recovery times. Identifying such relationships could be the first step in understanding symptom-based markers of concussion duration, which would inform the challenging return to play and return to class decisions. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]