His family confirmed Tuesday that Demaryius Thomas, a former NFL star, died from CTE last December at the age of 33.

After a brain scan by the Concussion Legacy Foundation, researchers at Boston University CTE Center diagnosed the four-time Pro Bowl wide receiver as having stage 2 chronic trauma encephalopathy. The study was released by Thomas’ family.

“When I was aware of CTE, and started to become familiar with the symptoms, Demaryius began isolating himself, and I saw other changes,” Katina Smith (Demyius’ mother) said in a statement. He was so young and it was terrible to watch him struggle. His father and me hope that all families are aware of the dangers associated with football. We didn’t want other parents losing their children the way we did.

Stage 2 CTE is characterized by “progressive behavior and cognitive and mood abnormalities.” Thomas’ family members claim that Thomas suffered from anxiety, panic attacks and depression in the years leading up to his death. Stage 4 is the most severe form of CTE, and is often associated with dementia.

“Like many others, we discovered stage 2 CTE within the brain of Demaryius Tom. My constant question is “When will enough be enough?” When will parents, athletes and the general public stop ignoring the dangers of American football and demand that the game is changed to reduce the subconcussive impacts? Dr. Ann McKee is chief of neuropathology at the VA Boston Healthcare System, and director of the VA-BU-CLF/UNITE Brain Bank.

The study was arranged by Thomas’ family by Dr. Chris Nowinski, co-founder of CLF and CEO.

Nowinski, who was a Harvard football player, said that the football community would not have known why so many ex-players struggle with neurological disorders. He thanked Katina Smith and Bobby Thomas for their faith in Dr. McKee. I hope that this serves as a wake-up call for high-profile former NFL players to realize that CTE is rampant and that they must take part in finding real solutions. CTE should be their top priority off-the-field concern.

Thomas is among more than 300 ex-NFL players who were diagnosed with CTE by McKee, the BU CTE Center research group.

Thomas’ cause has not been determined. In 2021, Thomas began experiencing seizures. McKee said to ABC News that she believes Thomas’ seizures were caused by severe traumatic injuries, which included a car accident and a fall on stone steps.

“CTE does not cause death.” You don’t die from CTE. McKee stated that CTE doesn’t cause death.

Thomas was a 10 year NFL veteran, playing for the Houston Texans, New York Jets and Denver Broncos. After the 2015 season, he won a Super Bowl title with the Broncos.

Thomas had 724 receptions for 9,763 yards with 63 touchdowns.