IF I understood the point correctly I don't think I agree that the song was intentionally a warning or the point was to comment on the negative effects of drug use...I think it's just a song that shows a depressed young male with serious underlying problems (which manifested later with the valium, ambien, etc.). The song captures that feeling of the "fuck me, my own well being is not a priority, why not take more" aspect of drug use. And then the lines about Hailie being grown up and behaving like he does show those fleeting moments of panic about how a drug addict's own self destructive behavior hurt their loved ones around them.
Woah, that was kind of scary, lol. /Stan post