Beaker manages her bi-polar disorder and takes responsibility for her health. So it was not a deal breaker for me. However, she knew that if she stopped trying to manage it - as many bi-polar folks do - then that is a dealbreaker for me. It's not having a mental illness but the refusal to cope, to deal, to manage, to take one's meds, if needed - that is my hard limit.
Now if it was a disease that had no treatment or was very difficult to treat, I would be more hesitant to get involved.