My experience was that once I had advised my employer that I had mental illness I was targetted, abused and their treatment of me escalted my illness. I did have perfromace issue in the end though, and they were stark as compared to the ultra high functioning person I had been (thus I set the standard for their expectations of me high, and it was obvious something was wrong as my performance slipped and I was emotionally very edgy).

Some employers, I am sure, are more considerate of people in this situation than others. But the sad thing was that this discimmination came from an employer that was the Department of Justice, from which all of Victoria, Australia's Anti-discrimmination laws emanate. So thus, I would be very careful about disclosing, as if they can discrimminate, anybody can. Very sad. They sacked me in the end with a euphemism called a "Targetted Separation Package, ie The Sack.