Writing a drug addict?

Have any of you ever written from the point of view of a drug addict? Do you think its possible to write this sort of thing well without any sort of personal experience with many drugs other than weed? I've just recently come up with the need to write about this sort of thing, though I don't want to make a fool of myself by doing it wrong xD

Could plenty of research help cure my lack of drug experience, or do I need to go do some heroin real fast? Not really, its too expensive LOL. Anyway, please help me out here! Tell me of any experience you've had writing this sort of thing, or give me any ideas you'd like? I dunno. This is all very rambly but I'm kinda in a bind at the moment xD help!

Hi, Neck! How sad that no one's stopped by to answer this. D:

It's very possible to write a story from that point of view though! And definitely research as much as you can. Don't actually do the drug though -- that would be kinda silly! You can do all sorts of things to get the information you need: lots of internet searching, library scrounging, interviews even! So if you want to write a story from this perspective, you'd just have to do the research.

Jabber is correct, Research research research.
However! Be careful that you don't sound too robotic from the research, remember that most drug addicts are people and therefore have emotions! usually lots of them!