For me it has always depended on how long I've been in the job, how well I know the people and how important they are in my overall life, etc.

I've disclosed twice, once to help my boss who had a mental health problem in her family be less secretive about it to me (there was just me and her and I could tell she wanted to talk about it but was afraid so I kept talking about my own experiences) and the other time at a long-term job where I knew everyone intimately and well and couldn't really get away with leaving for half a day once a week for therapy so just toughed it out and added to their teasing, doing it up worse than they could (banging my head against walls when frustrated, and otherwise acting "crazy" :-) It was a very closely knit, family business without personnel "people" and I was in the front office so was one of the personnel people so it all worked out over the course of the time I was there. I'm still good friends with the people there, even after having left 6 years ago.