Background/Aim: The purpose of this study was to evaluate the relationship between neuroendocrine hormones and clinical recovery after sport-related concussion (SRC). 
Methods: Seventy athletes (n = 38 male, n = 32 female) from nine interuniversity sport teams at a single institution provided blood samples. The cohort was comprised of 26 athletes with SRC (2 – 7 days post-injury), and 44 healthy athletes recruited prior to the start of their competitive season. Concentrations of 7 neuroendocrine hormones were quantitated in either plasma or serum by solid-phase chemiluminescent immunoassay. The Sport Concussion Assessment Tool version 5 (SCAT-5) was used to evaluate symptoms at the time of blood sampling in all athletes. Multivariate partial least squares (PLS) analyses were used to evaluate the relationship between blood hormone concentrations and both (1) initial symptom burden and (2) time to physician medical clearance. 
Results: An inverse relationship was observed between time to medical clearance and both dehydroepiandrosterone sulfate (DHEA-S) and progesterone; a positive relationship was found between time to medical clearance and prolactin. Cognitive, somatic, fatigue and emotional symptom clusters were associated with distinct neuroendocrine signatures.
Conclusion: Perturbations to the neuroendocrine system in athletes with SRC may contribute to initial symptom burden and longer recovery times.

Peripheral blood neuroendocrine hormones are associated with clinical indices of sport-related concussion.