this job has more to do with trust and attention to detail. people who are honest will not have a problem. candidates who was not successful either lied one way or the other about their background, or did not pass the drug test, or failed the personality test. The latter may be given orally over the phone. these are professionals who cannot be easily fooled. So just be honest about your past. Clue: will you report a co-worker who was doing drugs? Answer...think as if this was your business, wouldn't want to know, because mistakes can easily be made, much to the detrimental loss to this small company.