You know the law better than me and, of course, the laws should be followed. From what you have said, if someone discloses at work, you need to listen and consult your HR department before you advise and follow the companies policies.

The title of this thread is "How To Tell if Someone Is Faking Mental Illness"--that in and of itself implies to me that someone is voluntarily telling someone that they have some sort of mental illness. They might even just be telling a friend, family member or coworker who does not supervise them. If they have chosen to disclose then the law should first be followed if they do this at work but otherwise I still feel exactly what I have stated. What I would do might help some and not others--sometimes we don't know how to respond to people who are suffering perfectly. I admit I am not the queen of tact, an expert, or especially insightful but mostly I try to be responsive when people ask me for help. I have fallen short though. Many people need to be more educated about mental illness and how best to respond. Generally, if someone told me they were mentally ill (and it was bothering them), I would encourage them to seek treatment if they were not already in some kind of treatment and be willing to listen to them talk about it. It could be devastating to some people or discourage them from seeking the treatment they need if we say they are faking it.