I have told a few of my coworkers about my mental illness and as far as I know they haven't spread it around too much, and none of them have said anything hurtful to me. It just came up in casual conversation or someone was saying something offensive or incorrect about bipolar disorder and I told them that I have bipolar disorder and I do not behave the way they are describing. Most of my coworkers are around my age (mid 20s), and are a bit more open minded, and my supervisors are in the business of creating and maintaining wellbeing for their clients, so my guess is that they would extend the same philosophy to their workers (I'm a caregiver at an assisted living facility for elderly people). So it's not all dog-eat-dog. But I can see how some office jobs might be that way.