Concussion, also known as mild traumatic brain injury (mTBI),1 is a significant public health issue responsible for a variety of cognitive, emotional, and somatic symptoms and deficits (3). It is unclear why some individuals appear to recover relatively quickly while others suffer prolonged symptoms and impairments (4–7). Robust clinical means of diagnosis, prognosis, and treatment are also lacking (8–11). Research is hindered by an inadequate classification system for traumatic brain injury (TBI) (12), “poor” study quality (13, 14), disagreement about appropriate inclusion and exclusion criteria for concussion (8, 15), and an incomplete understanding of underlying pathophysiology (16–18). The heterogeneity and complexity seen in concussion further complicate research, particularly efforts to individualize treatment (19–22)
