I smoke a whole lot of marijuana, but I don't consider myself a pot head. Those that I would consider pot heads (in the more negative sense of the word) are those people whose pot habits cause them to make unreasonable decisions. Whoring oneself out for pot would be an extreme example. However, I would not consider that person a pothead if they whored themselves out for other things as well. Then they'd just be a whore who also smokes pot.