Numerous studies have linked concussions to weakened brain functioning. A study published in 2009 in the Journal of Neurotrauma found that while concussed athletes might perform normally in standard tests administered by medical practitioners to anyone suffering such an injury, they may still show suppressed brain functioning.
Although the common perception is that a concussion might be caused by one especially bad hit, a two-year study of high school athletes by Purdue University researchers found that mild traumatic brain injuries were in fact caused by a series of hits rather than a single blow to the head. In fact, even players never diagnosed with concussions still displayed changes in their brains as a result of the toll of the season.
Multiply that season after season over the career of an NFL veteran, and another picture emerges of the long-term consequences of year after year of hard impacts. In fact, as a result of the damage their bodies endure over their careers, NFL players are significantly more likely to abuse prescription painkillers than the rest of the population, according to a study published in the journal Drug and Alcohol Dependence.
When it comes to determining a cause for what drove Seau to the depression that led him to take his own life, chronic traumatic encephalopathy is certainly one of the more likely culprits. This condition had already been linked to other former NFL players, including Tom McHale, Andre Waters, Mike Webster, Terry Long and many others. All displayed symptoms ranging from depression to dementia to memory loss and more - all of which are signs of CTE. CTE, however, can only be diagnosed postmortem following an examination of the brain.
What caused Seau's death still needs to be determined. For its part, the NFL is more sensitive to concussions and brain injury recently than it has been in previous generations. According to research published in Sports Health in 2010, players who suffered concussions are now sidelined longer rather than being put immediately back into play as soon as symptoms subside.
According to the Centers for Disease Control and Prevention, around 3.8 million Americans, ranging from those competing in professional leagues to children playing youth sports, suffer sports- or recreation-related concussions every year.
Photo: Junior Seau, considered one of the best players in NFL history never to claim a Super Bowl ring, appears in uniform for the San Diego Chargers early in his career, which spanned 16 seasons. Credit: Corbis Images.