I'm in the military and knew that if I ever sought treatment my career would likely be over. Well, after enduring MDD in the closet for 4-5 years I finally asked for help, and sure enough, I won't be allowed to reenlist beyond the 20-year mark. (I have 17 years in now.) I am grateful that they are allowing me to retire instead of kicking me out, but their attitude shows how old-fashioned and (to some degree) inept military physicians can be. My choices are to either not say anything, be a poor performer and a danger to my team, and I'll be allowed to stay in to 30 years, or- ask for help, feel much better and be a better service member, but be forcibly retired because I'm on meds. The proverbial Catch 22...
As for the stigma associated with mental illness, I have seen some changes in a few of the people who know- mostly in the form of politely excluding me from social activities I was invited to before and so forth. It bugs me, but not enough to let it get me down. At 45 years of age my world rarely centers on what the people around me think- especially coworkers. ;)
My wife is supportive and my (grown) kids don't know- and that's the way I want it. So all in all while I do notice the stigma in the work environment, it doesn't impact me too much socially as very few people know about it.