I'm actually on SS disability for OCD/anxiety/depression, though other things were going on with me at the time. I didn't know what and was still searching for answers (probably these seizures and Lyme). I was lucky to get it though. What helped, I think, was...well, two things...
1) I had a lonnng history of OCD/anxiety/depression, documented by seeing lots of doctors for it to no avail. Nothing ever helped.
2) My employer at the time wrote me up twice...once for answering the phone (and I was a receptionist), and that same week for not answering the phone (when the vet, somebody I thought I should listen to, walked out as the phone was ringing and yelled, "Elizzza, don't answer the phone!" While I turned to look at her with a 'huh?' look on my face, another girl at the front answered the phone, and I got written up 2 minutes later). I knew they had intentions of firing me by the second write-up (probably because I was the 'voice' and 'pen' for everyone else there that was unhappy with this new company that was screwing us all). But I went in the day after this second write-up, first thing - before they had a chance to write me up a 3rd and final time - told them I was taking short-term disability leave (so I'd at least get 60% of my pay for like 3 months and maintain my health insurance), and immediately filed for SS disability.
It all worked out though...I shouldn't even have been working with how severe my OCD/anxiety/depression was (and still is). And by the time my short term ran out, my SS kicked in (retroactive to the date I applied). Plus, there were some people (in high places) with this company who truly respected me and knew I was in the right (and told me so), and they really looked out for me. Let's just say they allowed me to get short-term disability much longer than I was supposed to, months longer, and I never had to pay them back. When the head guy (months later) tried to accuse me of robbing them (for cashing these ongoing checks), I pointed out that I'd called the girl I was supposed to call multiple times, told her it was time to stop the checks, asked her if I should send them back, and she had said 'no' multiple times...to just cash them...she'd take care of it. Obviously I didn't spend these checks (in case they would've asked for them back), but it was nice screwing them back after what they'd done to me...and I wasn't even trying to! Bet they didn't think I was smart enough to file for short-term (on the basis of psych reasons) before they had the chance to fire me. I'd applied for SSI once years before this though...didn't get it. SS I didn't even qualify for (yet) back then.