Hiring nurses and background checks

Hi to all,
I have a very important question and I hope I can get the facts here...I am new to this site. I was wondering what kind of background checks are performed when hiring an RN. Can they find out if someone has been hospitalized for psychiatric reasons (for instance, someone with a 5150), even if the person was brought to a mental health unit by paramedics and not a cop...and also if they have no criminal record? I was diagnosed with bipolar disorder and have been hospitalized more than once. However, I have never harmed myself or others. I am about to apply for nursing school and I want to find out my rights...is this medical information protected when applying for a nursing position (or any other, for that matter)? Thanks for your time...please email me back at lisaalmonds2@aol.com.
Lisa