Don’t want to be a wet blanket here, but I would caution against using celebrities as a barometer for social stigma.
For one, mental illness has always been considered acceptable in creative fields — the “troubled genius” and the “tortured artist” — so it’s relatively easy for pop stars and actors to be open about it. It’s actually good for them. It gives them depth, a mystique, ex. Brian Wilson of The Beach Boys.
There’s almost no stigma for them socially and no (negative) consequences professionally. No record companies are going to decline a record deal with Lovato because she is bipolar. No one will refuse to cast Zeta-Jones.
Average people with mental illness can’t post about it on social media out of fear their employer, current or future, will read it and discriminate against them. So while it’s good that celebrities use their positions of privilege to talk openly about their illness I’m not to terribly hopeful that it, in itself, will result in any reduction of stigma for the rest of us. They’ll be called “brave” and “misunderstood” while we’ll be called “crazy” and “unreliable”