PITTSBURGH — Former Pittsburgh Steelers lineman Terry Long committed suicide by drinking antifreeze, a revised death certificate shows, and did not die as a direct result of football-related head injuries.

The Allegheny County coroner ruled in September that the 45-year-old Long, who had attempted suicide before, had died of meningitis. The condition, a swelling of the lining of Long's brain, was caused by football-related "chronic traumatic encephalopathy," also known as "punch-drunk syndrome," said the coroner at the time, Dr. Cyril Wecht.

But a revised death certificate, which Wecht's office never publicly announced, was filed Oct. 19, listing the manner of Long's death as suicide from drinking antifreeze. The ruling was changed when outside laboratory tests on Long's tissue and urine showed they contained ethylene glycol, the active ingredient in antifreeze, county officials said.

Joseph Dominick, chief of operations at the medical examiner's office, said Thursday that the antifreeze was what caused the swelling of the brain and the brain lining, and the football-related brain injuries were a contributing factor to the death.

Long died June 7, about five hours after he was found unresponsive in his suburban Pittsburgh home.

He had started at right guard for the Steelers from 1984 until 1991, when he attempted suicide with rat poison after he was suspended for violating the NFL's steroid policy. Long later rejoined the team, although he was not re-signed after one season.

In March, Long was indicted by a federal grand jury on charges he fraudulently obtained loans for a chicken-processing plant which prosecutors allege he burned to the ground for the insurance money. At the time he died, Long's neighbor said he was separated from his second wife and was depressed about that, as well as the federal charges he faced.

The original findings about Long's death reinvigorated the debate over the dangers football players, particularly linemen, face from repetitive head injuries.

The medical examiner felt Long's history of brain injury was still a "significant factor" in the death and that he would be remiss in not mentioning it in the updated report, Dominick said.

Dr. Bennet Omalu, a neurologist who worked on Long's autopsy and is still with the medical examiner's office, told the Pittsburgh Post-Gazette that people with chronic traumatic encephalopathy can suffer from depression.

"The major depressive disorder may manifest as suicide attempts. Terry Long committed suicide due to the chronic traumatic encephalopathy due to his long-term play," Omalu said.

Omalu didn't immediately return a call for comment from The Associated Press on Thursday.

Steelers team physician Dr. Joseph Maroon, a neurosurgeon and nationally recognized expert on concussions, said there's no facts establishing that Long's football injuries had anything to do with causing his death. Maroon said someone who suffers head trauma can develop depression and short-term memory problems, but that "doesn't make someone an arsonist, one who fraudulently obtains money from the government and ingest rat poisoning and antifreeze coincidentally with being indicted by the federal government."

"I've seen hundreds of patients with traumatic brain injuries, from all sorts of accidents, including sports," Maroon said Thursday. "I have never seen this kind of anti-social behavior as a consequence of a traumatic brain injury."