Here's an excellent article on the impact of mental health issues in the workplace.
It's hard to focus on your work when your child is hallucinating.
I've experienced this so many times - "please come home, he's very manic and throwing things around..."
This stigma extends beyond those directly stricken to family members. Parents of children with mental illness are often viewed as guilty by association, unfairly perceived as the cause of the illness—the source of harmful child-rearing practices—when the origin is mainly biological. Parents and other family members feel shame and a sense of failure.
Nobody knows this better than my wife and I. Having lost our adult son to issues associated with bipolar disorder, we tried everything, and heard every piece of advice when he was growing up.
This is a very real problem, but I don't see any significant changes being made in attitude or workplace policies.