Former NFL running back Larry Johnson says he believes he has chronic traumatic encephalopathy, a brain disease that doctors say can be caused by repeated blows to the head.
CTE can be only diagnosed after someone dies.
Johnson, who last played in the NFL in 2011, says he has mood swings, headaches and forgets a lot of things, which he calls "Blank spots." He also says he is prone to violence and self-destructive impulses.
"If I can't remember who I was, I've got YouTube; I've got music videos that I'm making for myself, so when I watch these things I can remember," Johnson tells the Washington Post. "I'm trying to get these things in order so she knows who I am and what I came from."
The two–time Pro Bowler wonders if he will end up like former New England Patriots tight end Aaron Hernandez.
Hernandez committed suicide in jail in April while serving a life sentence for murder.
"A bittersweet thing: I'm going to be free of everything that's holding me down," Johnson said. "The same way Aaron [Hernandez] thought: I'm going to be gone from this world, but I'm still going to be able to take care of my child, because that's all I care about."