Does football cause brain damage?

he critical issues in the clinical management of sports concussion include confirming the diagnosis, excluding structural abnormality and determining when players can be safely returned to competition. Despite the apparent simplicity of this process, the management of this one injury seems to provoke more debate than all other sports injuries combined. Unfortunately, this debate has largely been played out in the news media rather than through scientific journals. Complex issues have been oversimplified and distorted, causing significant alarm over putative long-term risks and concern over how an acute injury should be managed. One source of anxiety is the phenomenon of chronic traumatic encephalopathy (CTE). The concept of “subconcussive” head injury has also evolved, with the concern that the cumulative effect of these ill defined “injuries” can lead to permanent structural brain injury.1,2 In this issue of the Journal, Gilbert and Partridge argue for preventive measures that in many cases have already been instituted.3 Tragic stories of athletes who have not been managed appropriately or who have failed to fully disclose their injury to team medical staff, with catastrophic outcomes, are regularly aired in the media and have driven legislators in the United States to propose regulatory measures that restrict medical management of concussion in ways to which no other medical condition is subject. In addition to proposed congressional legislation, more than 40 US states have considered or passed bills relating to the management of sports concussion. In some states, mandatory preseason cognitive testing and other paradigms are included. Ironically, this focus on media anecdote and government regulation has occurred at a time when we know more than ever about the science of concussion in sport. Although CTE in American footballers and wrestlers has been highlighted as a novel risk, scientific study into chronic brain injury in athletes extends back almost a century. What remains unclear is whether all athletes who suffer recurrent concussive (or subconcussive) brain impact are at risk of such sequelae, or whether a subset of athletes, presumably with a genetic predisposition, are at higher risk of CTE. A further, more likely, possibility is that retired athletes may simply suffer from an incipient neurological illness (such as frontotemporal dementia) unrelated to their sporting career.1,2 Mental health issues (such as depression) have also been reported as a consequence of sports concussion, occurring in 11% of retired footballers, with an association with recurrent concussion.1,2,4 However, depression and anxiety symptoms occur in 15%–60% of subjects after traumatic brain injury from any cause and are also highly prevalent in this age group in the absence of trauma.5 T