I've recently read Methland, a story about the effects of methamphetamine use on a small town in Iowa. (I also assigned it to my crime class).
Now, I don't naturally gravitate toward a critical/ conflict theory of sociologist (i.e., one that focuses on the oppression by the elite), but this book describes the very real ways that big pharmaceutical companies, and their lobbyists, have made the meth epidemic what it is today.
Meth is made with pseudoephedrine--the stuff in cold medicine. Regulating it seems like an easy way to hinder the production of meth, but on numerous occasions the big drug companies fought against it. They didn't want to keep track of imports or sales. In fact, it's possible to make psuedoephedrine so that it can't be used for meth, but they fought that too. I understand that these companies are charged by their shareholders to maximize profits, but at what cost?