I am sorry you made it all the way through nursing school and became a nurse and this happened, (having your mental health history brought up against your will).
Although there is no shame in having a mental health history nursing homes and hospitals are not owned by nurses ? They are owned by private corporations that seek to keep their yearly insurances at the lowest rate possible.
Although I think it is against the law in my state I believe given the nature of the job (I am a lpN so it is chiefly a med pass for my position), it is appropriate for my boss to know if I am prescribed a controlled substance or psychotropic drug and whom it is prescribed by. I believe communicating about this early on, (even though it should NEVER be asked of you, legally), is the best bet. It will cover You in the rare chance an accident happens at work that you are responsible for or even on the periphery of, which can happen to ANY nurse at ANY time. Covering yourself is key.