Updated

A former college football star who disappeared in the Michigan wilderness during a fishing trip died of pneumonia caused by inhaling his vomit, after he became disoriented possibly because of painkillers combined with having a degenerative brain disease, according to an updated autopsy released Thursday.

The report said Cullen Finnerty's anxiety and paranoia in the woods the night of May 26 may have been exacerbated by an "elevated" level of oxycodone and chronic traumatic encephalopathy, the brain disease that has been found in a number of ex-football players.

Finnerty's brain was studied at Boston University's Center for the Study of Traumatic Encephalopathy, which said Thursday the severity of CTE was moderate and it's "highly unlikely" the disease alone led to his death.

"CTE possibly affected his judgment, insight and behavior, but there are other factors, including the use of medications prescribed by his doctor, that most likely contributed to the circumstances surrounding his death," the center said in a statement on behalf of the Finnerty family. "Unfortunately because of the complexity of his medications and medical status, it is impossible to determine the specific combination of factors that led to his tragic death. "

Kent County Chief Medical Examiner Stephen Cohle said Finnerty, 30, became incapacitated before inhaling his vomit in Lake County 65 miles north of Grand Rapids.

Though relatives reported the former Grand Valley State University quarterback had a number of alcoholic drinks the day he died, Cohle said his blood-alcohol level was "negligible" and didn't contribute to Finnerty's incapacitation.

The report said it's likely Finnerty had anxiety, disorientation and paranoia from being alone in the woods while waiting for in-laws to pick him up. Cohle said the pain medication was prescribed to Finnerty for back injuries likely sustained during his football career.

Finnerty's father, Tim Finnerty, told The Associated Press on Thursday that his son also was taking a thyroid medication at the time of his death, and the family is concerned high doses could have caused him to become sick and confused.

"None of this (news) is going to bring Cullen back," Tim Finnerty said. "The only people that will know what happened will be Cullen and God."

An initial autopsy conducted the morning after Finnerty's body was found determined that he had a "slightly enlarged heart and slightly cloudy lungs" but "no trauma to the body at all." The final report includes toxicology results and the determination that he had CTE.

Boston University's center for study of the disease reported in December that 34 former pro football players and nine who played only college football suffered from CTE.

The NFL faces lawsuits by thousands of former players who say the league withheld information on the harmful effects of concussions. The NCAA also is being sued over its handling of head injuries.

Tim Finnerty, who coached football for 35 years, said it's important to keep researching CTE and possible links to injuries not only in football but hockey, soccer and others sports. But he said the life lessons and benefits of playing football are "substantial."

Finnerty's wife told investigators that he had a past addiction to painkillers but had not taken any drugs since spending time in a rehabilitation center more than a year earlier. Jennifer Finnerty said it wasn't the first time he had a "paranoid" episode.

Instead of driving home from Detroit a year-and-a-half earlier, he took off for Grand Rapids in western Michigan due to fears the FBI would follow him, she said. She said her husband remained in a state of panic for four to five days.

Cullen Finnerty, his brother-in-law Matt Brinks and father-in-law Dan Brinks went fishing the night of May 26. The Brinks dropped off Finnerty around 8:30 p.m. and watched as he boarded a small personal inflatable pontoon boat and floated down stream.

The plan was for the Brinks to pick up Finnerty in about 30 minutes, but as it turned out, it was the last time they would see him alive. His body was found May 28 within a mile of where he had disappeared.

In two brief phone conversations with family members, Finnerty sounded disoriented and complained of being tailed.

Finnerty led Grand Valley, a Division II school, to more than 50 victories and three Division II national titles, the last in 2006. He briefly was a member of the Baltimore Ravens and later the Denver Broncos but never took a snap in a regular season game.

"He didn't run out of bounds. He put his head down and got the first down. He wasn't the guy that threw the ball away. He probably took some hits he shouldn't have," said Scott Boyd, a family friend who was on the search party that bond the body. "But he was a leader on and off the field. He played to his fullest. ... He was always upbeat and positive and smiling and had a warm handshake and hug for you."