LAUSR

CONTEXT Head injuries are risk factors for chronic depressive disorders, but this association remains poorly explored with regards to concussion. OBJECTIVES The objective of this review was to evaluate the incidence of depressive symptoms and depression after sports-related concussion. We also endeavored to identify the response elements regarding the pathophysiology of these symptoms. METHODS A systematic search of PubMed and Embase was conducted focusing on papers published until 1st December, 2016, according to PRISMA criteria The following MESH terms were used: (concussion or traumatic brain injury) and sport and (depression or depressive disorder). RESULTS A depressive disorder can appear immediately after a concussion: depressive symptoms seem to be associated with the symptoms of the concussion itself. A depressive disorder can also appear later, and is often linked to the frequency and number of concussions. Furthermore, the existence of a mood disorder prior to a concussion can contribute to the onset of a depressive disorder after a concussion. LIMITS There is an overall limit concerning the definition of a depressive disorder. In addition, when these studies had controls, they were often compared to high-level athletes; yet, practicing sport regularly is a protective factor against mood pathologies. CONCLUSIONS Depressive symptoms after a concussion seem to be associated with postconcussion symptoms. Repeat concussions can contribute to later-onset major depressive disorders. However, playing sports can protect against major depressive disorders: thus, it is essential to evaluate concussions as accurately as possible.