Changes in the brain’s white matter may help explain why some former professional football players develop cognitive dysfunction and depression later in life, according to a study published in JAMA Neurology today.
High-profile suicides of former National Football League (NFL) players who developed cognitive deficits and depression later in life have sparked debate about whether the frequent concussions suffered by some of these athletes may contribute to lasting neurological damage. A 2009 study found brain degeneration in former athletes who had experienced brain trauma. In addition, a 2009 survey of former NFL players suggested an elevated rate of depression or memory problems among former players compared with men in the general population.
To further probe the relationship between long-term mental and cognitive health and participation in the NFL, a team of researchers conducted a study comparing 14 former NFL players with cognitive impairment or depression with 20 healthy former players and with 85 men who had not played professional football. Compared with the non–football players, the former players had higher rates of depression and cognitive impairment. Using imaging tests, the researchers also found measurable differences in the white matter of the brain of cognitively impaired players, compared with the cognitively normal former players and nonplayers. The affected brain areas play roles in memory and verbal tasks, the same functions in which impaired former players experienced difficulties.
The study’s lead author, John Hart Jr, MD, of the Center for BrainHealth at the University of Texas at Dallas, discussed the findings with news@JAMA.
news@JAMA: What does your study tell us about the relationship between playing professional football and later cognitive difficulties?
Dr Hart: Not everybody is having difficulties. The imaging markers are giving us the idea that a lack of white matter connectivity may be causing some of the cognitive and mood difficulties former players are having. This is providing some explanatory information and giving us clues to potential diagnostic markers.
news@JAMA: What does your study tell us about the role of concussions in these later-life problems?
Dr Hart: It’s not a straightforward relationship. The individuals who had problems didn’t have a different number of concussions than those who didn’t have problems. It wasn’t a clear predictor of future problems.
One surprising thing we found was that postconcussive mood disorders can be present without typical symptoms. In the long-term or short-term, physicians need to ask about symptoms of potential mood problems. Symptoms that are more likely to occur in these individuals include changes in energy level, weight, sleep, anxiety levels, and having trouble making decisions. These are not standard postconcussive questions. It’s something we need to keep an eye on.
news@JAMA: What factors may be predictors of which individuals will develop later problems?
Dr Hart: We are looking at the number of years played, subconcussive injuries, and genetic risk factors that could play a role.
news@JAMA: Might there be baseline differences between professional football players and the rest of the public that explain the differences you noted?
Dr Hart: We ran a bunch of controls. We found individuals for the control group who were the same age, had the same IQ, and educational background.
news@JAMA: What’s next for your research?
Dr Hart: We’ll be following our group longitudinally and will see them each year. We are also adding new people to the study. We may also look at young people closer to the time of injury, follow them longitudinally, and conduct preventive and treatment trials.
news@JAMA: Do you have any advice for parents and physicians hoping to protect young football players from long-term harm?
Dr Hart: I would follow the current safety guidelines. Back [when these individuals played] we didn’t have guidelines on resting after a concussion; players went right back into the game. We’ve seen big changes [in the guidelines] already that may obviate this from happening in individuals playing nowadays.