This position requires us to do a background check, and drug screen. Are there any issues we need to be made aware of that might hinder your employment with us?

This is a question that is designed to test your truthfulness as a person. The interviewer knows that you might lie to save face during an interview if you are aware of a situation from your past. This is an opportunity to be forthright and open about mistakes you have made. Don't dwell on them, but discuss them with the hiring manager if you feel that they will impact your ability to be hired. Sometimes, hiring an overqualified individual can mean that they will leave when a better opportunity arises. Talk to the interviewer about why this position would be satisfying for you in the long term.