Well I'm on SSI after having severe PTSD. I was on public assistance/welfare and my doctor had to fill out a form saying that I was unable to work. Then public assistance/welfare got the ball rolling for me to apply for disability.

They sent me to their doctor and got screened and everything...next thing I knew I was approved for SSI. That was back in 2000/2001 and I'm still on SSI.

A lot of people I know, though, have to appeal repeatedly because SSI doesn't approve their case...so I guess I was really lucky.