Tyler Hilinski, the Washington State quarterback who took his own life in January , had chronic traumatic encephalopathy, the brain disease known as CTE, at the time of his death, his parents revealed in interviews with The Today Show and Sports Illustrated.

Hilinski was just 21 years old when he was found dead of a self-inflicted gunshot wound after not showing up for practice on Jan. 16.

Following Hilinskis death, the Mayo Clinic asked the family if it could conduct an autopsy of Tylers brain. It revealed that Hilinski had Stage I of CTE, a degenerative brain disease some researchers believe is a result of repetitive head trauma.

It was a shock to get those results and find out he had (CTE) and to realize that this sport that he loved may have contributed to that diagnosis, Kym Hilinski said on the Today Show.

Added Mark Hilinski: The medical examiner said he had the brain of a 65-year-old, which is really hard to take. That was difficult to hear.From Sports Illustrated:

The Mayo Clinics findings arrived next. Kym read the first sentenceAfter reviewing the tissue we can confirm that he had the pathology of chronic traumatic encephalopathy (CTE)and started to reconsider her entire search. The diagnosis was Stage I, the lowest level. But still, Tyler had been just 21, he hadnt played that much in college and for most of his life he manned the most protected of positions. If he had CTE, anyone could. She read that depression was one symptom for Stage 1 and a doctor told her Tylers brain looked like that of a much older, elderly man.

Hilinkski was Washington States backup quarterback in 2016 and 2017. He saw significant action in 2017, throwing for 1,176 yards, seven touchdowns and seven interceptions in eight games. Most notably, he led the Cougars to a dramatic triple overtime comeback win over Boise State.

Later in the year, Hilinski threw for 509 yards in a loss to Arizona. With starter Luke Falk sidelined, he made his first career start in the Holiday Bowl against Michigan State on Dec. 28.

The family told SIs Greg Bishop that they noticed a change in Tyler after the Arizona game.

Last October, Tyler relieved Falk late in the second quarter at Arizona, down 207. In just over a half, he completed 45 passes for 509 yards and accounted for four touchdowns. He also threw four interceptions and Washington State lost. Sensing some distress in his younger brotherwho also mentioned sustaining a hit that had rocked himKelly sent the rest of the family text messages saying Tyler was having trouble putting the defeat behind him. Kelly even drove to the Cougars game at Utah on Nov. 11 and consoled his brother on the balcony outside Tylers hotel room the night before, reminding him he couldnt win every time in triple OT. Why not?, Superman responded. He felt like he let everyone down, Kelly says.

His family noticed other, seemingly minor changes in Tyler after the Arizona loss. He wasnt as responsive to texts and calls the rest of the season, particularly in the lead-up to the Holiday Bowl, where he started in a loss to Michigan State. At one point, Mark asked Kym if she thought something was wrong with Tyler, and they determined he was just busy with classes and football and student life. That was the most difficult conversation, looking back. At a minimum, they had known something. The reality is we missed it and we let him down, his father says.

With Falk off to the NFL, Hilinski was expected to take the reins as WSUs starting quarterback as a redshirt junior in 2018.

In the months since Tylers death, the family has started the Hilinskis Hope Foundation , a non-profit organization with the goal of keeping Tylers memory alive and generating the funding necessary to support programs that will help destigmatize mental illness.