I've never seen that question on a job application. I think it would be foolish to put that information out there with out being specifically asked. And I don't see how it would be dishonest to not volunteer information that isn't relative to the specific job you are going to do.
A resume/job application is supposed to sell you to your potentional employer. Highlight your experience relative to the job. Highlight what is going to set you apart from other applicants (in a good way). Highlight your skills. Unless being a drug addict is your best selling point or going to interfere in your ability to perform required job duties, what is the point in mentioning it?
ANd if you have gaps on your resume due to your addiction, you can answer truthfully, taking care of personal business. No need to put a big red A on your chest. Especially in this economic environment.
I used to use drugs. Now I don't. How is that relative to anything in my professional life. I'm clean. I show up for work every day. I do a good job. It's nobodies business but my own. - and those I choose to share it with.