New studies by the Center for the Study of Traumatic Encephalopathy, reported Tuesday they found overwhelming evidence that repeated concussions cause severe brain damage, after studying the brains of dead athletes.

Ted Johnson had brain damage so bad after his NFL career that he struggled for years in day to day activities. After looking at the information on the brains of athletes who died young, the results found are staggering.

I can definitely point to 2002 when I got back-to-back concussions. That's where the problems started, said Johnson, who retired after those two concussions. The depression, the sleep disorders and the mental fatigue.

I'd go see my kids for maybe 15 minutes, said Johnson. Then I would go back home and close the curtains, turn the lights off and I'd stay in bed. That was my routine for two years. Those were bad days.

Chris Nowinski, a football star at Harvard before wrestling professionally with World Wrestling Entertainment, knows well the impact of concussions.

His dreams of a long career wrestling were dashed by a kick to his Chin, which caused him to black out and effectively ended his career, capped a career riddled with concussions.

My world changed, said Nowinski. I had depression. I had memory problems. My head hurt for five years.

The idea that you can whack your head hundreds of times in your life and knock yourself out and get up and be fine is gone, Nowinski added. We know we can't do that anymore. This causes long-term damage.

The Center for the Study of Traumatic Encephalopathy, along with other research institutions, identified traumatic encephalopathy in the brains of late NFL football players John Grimsley, Mike Webster, Andre Waters, Justin Strzelczyk and Terry Long.