Widow of former NFL star Vincent Jackson speaks out for 1st time since his death, reveals CTE diagnosis

Former NFL star Vincent Jackson died in February and now as his widow reflects on his health and life, doctors have confirmed Jackson had Stage 2 CTE, a degenerative brain disease associated with many former football players.

Lindsey Jackson sat down exclusively with ABC News' Juju Chang in her first interview since her husband's death and revealed the stunning diagnosis.

"Vincent was an amazing dad -- he would do anything for his kids," she said.

From the outside, Vincent Jackson appeared to be acing life after a storied NFL career. However, Lindsey Jackson said for years her husband suffered from memory loss, erratic behavior and kept turning to alcohol.

"He shared with me once that ... alcohol made him feel calm and made him feel like himself. And that his brain was really fuzzy. And that this made it not fuzzy,” she said.

The couple decided they needed a break and he lived at a hotel. She said the family grew increasingly concerned about his mental health. Then, Vincent Jackson was found dead on Feb. 15.

"That was a hard day. We-- had the sheriff come to our house and-- let us know,” she said. “I had been telling the kids and letting them know that dad was really sick. And he's gonna get better and he's gonna ... be back. And here they are in our living room and telling us that's not the case."

The family decided to donate his brain to researchers at Boston University's Chronic Traumatic Encephalopathy (CTE) Center.

The results showed Vincent Jackson had Stage 2 CTE, which was a shock to his family since he was never diagnosed with a concussion during his 12 seasons as a wide receiver in the NFL.

"I felt just really bad for him. He didn't know he had it. And I think had he known, he wouldn't have felt so ashamed or alone," Lindsey Jackson said tearfully. "No one should have to die in a room by himself."

Dr. Ann McKee, the leading expert and researcher of CTE and neuropathologist at Boston University who diagnosed Vincent Jackson, further explained the findings.

"His was stage two because he had multiple areas of the brain that were affected on both sides of the brain ... most of them in the frontal lobe," she said. "They might have violent behaviors either physically or verbally. They're often depressed and moody; they may or may not have mood swings."

McKee said there is too much focus on concussions and not enough on the cumulative effects of head trauma over the years.

"I think the NFL needs to overhaul their awareness campaign to concentrate on repetitive head hits that don't rise to the level of concussion," McKee said.

In a statement provided to ABC News, the NFL said: "The NFL continues to mourn with the families of Vincent Jackson as well as Phillip Adams and all those who lost their lives in Rock Hill, South Carolina in April. These are incredibly tragic situations, and our hearts go out to all who have been affected. Phillip Adams and Vincent Jackson’s diagnoses underscore the need for independent scientific research related to the prevention, diagnosis and treatment of traumatic brain injury (TBI), concussion and chronic traumatic encephalopathy (CTE). There is more to learn about head injury and related illness, and while the NFL is funding that important work, we also continue to make tangible progress in protecting players and making our game safer."

The statement continued, "Additionally, in collaboration with the NFL Players Association, the NFL provides comprehensive mental wellness resources to current and former NFL players and the NFL family. These include mental health education programs, access to skilled clinicians and substance abuse experts and a platform that connects current and former players with trained counselors who are on-call 24 hours per day, year-round. We encourage current and former NFL players – and anyone who may be suffering – to seek help, prioritize their mental wellness and take advantage of mental health resources. It’s important to address."

Lindsey Jackson said she is sharing her family's story now in hopes that it could raise awareness and help other families connect the dots.

"In his mind, it would have explained why he couldn't fix anything," she said.

His family told ABC News the final autopsy will be out Thursday. Presently, CTE can only be diagnosed post-mortem.