The analysis by doctors affiliated with the Sports Legacy Institute suggests that the brain damage could have risen from concussions caused over years in the boxing ring. This could have definitely led to the killings at Benoit's suburban Atlanta home, they say.
Another hypothesis doing the rounds, is the use of steroids, especially since anabolic steroids were found in Benoit's home. Tests conducted by authorities had showed Benoit to be having 10 times the normal level of testosterone in his system before he died.
The Sports Legacy Institute which researches the long-term effects of concussions, was able to release the recent findings using samples of Benoit's brain tissue provided by the Georgia Bureau of Investigation.
The Massachusetts-based institute's president is former pro wrestler Christopher Nowinski. He had quit the ring after a kick to the head. Nowinski still has ties with World Wrestling Entertainment Inc., which runs the league he and Benoit were in.The WWE company has maintained that steroid use did not cause Benoit to snap.
Yet says Dr. Robert Cantu, a member of the Sports Legacy Institute and who also is chief of neurosurgery service at Emerson Hospital in Concord, Massachusetts: "Despite the results of the institute's tests, there was no way to know if Benoit's concussions contributed to the murder-suicide.
"Whether it is the sole factor I believe is speculation and I will not go there," Cantu added. He did say that the level of brain damage Benoit had could cause depression and irrational behavior.
Incidentally, Benoit's brain has shown the same degenerative processes that doctors working for the institute found in the brains of three men who had played pro football and committed suicide. There were abnormal protein deposits caused by trauma to Benoit's brain, Cantu informed. He added that so far there was no evidence that steroid use could cause such protein deposits.
Investigators permitted the institute to test Benoit's brain tissue after getting the go-ahead from his father, Michael Benoit, who lives near Edmonton in Ardrossan, Alberta.
Michael Benoit was quoted Wednesday that he agreed to the testing because murder-suicide was out of character for his son. He also disclosed that after the killings, he discovered a diary written by his son that showed his son was having problems.
"After reading the diary, I would have thought it was written by someone who was extremely disturbed at the time," Michael Benoit said.
He did not elaborate, but he did say a friend told him that prior to the murder-suicide, Chris Benoit had been wearing a rosary, which he said was also out of character.
Said Michael Benoit:"I think it's the extreme that is in the wrestling industry today. The human skull is not built to get hit by a chair or something."
According to Nowinski, concussions can happen in pro wrestling even though many of the moves are staged."I got four concussions in three years as a professional wrestler," says Nowinski. "A lot of concussions happen from mistakes", he added.
According to prosecutors, Benoit, 40, strangled his wife with a cord, used a choke hold to strangle his 7-year-old son, placed Bibles next to the bodies and hanged himself on a piece of exercise equipment the weekend of June 22.
It is also reported that Benoit's personal doctor, Phil Astin, prescribed a 10-month supply of anabolic steroids to Benoit every three to four weeks between May 2006 and May 2007. Astin meanwhile, has pleaded not guilty to federal charges of improperly prescribing painkillers and other drugs to two patients other than Benoit.