I need to know about requirements to work in a drug rehab center?

Because of a friend's drug addiction, I have recently decided to have a career in a drug rehabilitation.

I've wanted to be an RN for a while, but I'm sure there are other requirements to work with patients in drug rehab centers.

I don't really need to know the actions of the people and what I'll be dealing with so much as what the REQUIREMENTS are.

If you know of any links or have any advice, please let me know.

: http://alcoholdrugstreatment.info/i-need-to-know-about-requirements-to-work-in-a-drug-rehab-center