To the Editor It has become fashionable to posit that concussion-like symptoms result from preexisting mood and behavioral disorders instead of traumatic brain injury. Iverson et al1 have produced a study of impressive size, scope, and statistical depth supporting this thesis. While it goes to great lengths to establish factors such as substance abuse, attention-deficit/hyperactivity disorder, psychiatric conditions, and migraines as primary predictors of reporting of concussion-like symptoms in the high school population, it fails to investigate whether these factors are the result of concussions and/or repetitive head trauma earlier in childhood.2,3 A sample of high school athletes, particularly those participating in collision sports such as football, includes those who may have started organized play as early as 4 years of age. It would imply that some participants in the Iverson et al sample may have been exposed to more than a decade of repetitive head trauma before inclusion in this study. The study does attempt to account for those with a history of concussion, but it is well recognized that most concussions in youth league sports are neither well detected nor documented.4 This study and numerous previous studies5 have demonstrated that those who have had documented concussions are more likely to have future concussions. In that light, clinicians must document not only sex and preexisting conditions of the patient but also whether he or she has a history of participating in collision sports. Until sufficient data are gathered, it would be irresponsible to attribute symptoms to conditions that may have been acquired as the result of mechanical insults to the brain. It could encourage clinicians to clear patients who present with concussion-like symptoms to return to play who are affected by brain damage, thereby risking further irreversible impairment.
Comrie D. Attribution of Concussion-Like Symptoms and History of Collision Sports Exposure. JAMA Pediatr. 2016;170(4):399-400. doi:10.1001/jamapediatrics.2015.4646