O.J. Simpson

O.J. Simpson's erratic behavior over the years has painted the former football star as a dangerous person -- maybe even a monster. But as the effects of CTE become more understood in the medical community, Simpson is starting to be seen as someone who may be afflicted by the disease himself.

Dr. Bennet Omalu, the groundbreaking physician who discovered CTE, and who was recently portrayed in the movie "Concussion" by Will Smith, is all but convinced.

"I would bet my medical license that he has CTE," says Omalu to PEOPLE Magazine. He adds: "Given his profile, I think it's not an irresponsible conclusion to suspect he has CTE."

CTE cannot be formally diagnosed in a living person -- a study of the brain post-death is the only way to confirm a case. But CTE has become associated with a variety of symptoms evident in life, including mood swings, violence, emotional reactions to mundane stresses, and even criminal behavior.

Simpson may be aware of some of those changes. In a sworn statement given during a 2008 trial for armed robbery, Simpson tried to portray himself as someone whose judgment had been impaired by years of head trauma playing football.

"I was knocked out of games for such head blows repeatedly in the 1970s and other times I continued playing despite hard blows to my head during football games," he said, according to PEOPLE.

PEOPLE also reports that friends and associates close to him have observed dramatic changes in his behavior, and now see him as an unstable individual with unexplained mental problems.

The former Heisman Trophy winner is up for parole in 2017. But if he does suffer from CTE, it's unlikely his behavior will change for the better.

In 2014, HBO's Real Sports did a story about the connection between concussions and domestic violence. Here is part of the report:

More NFL: NFL Players Discuss Use Of Marijuana For Pain Management