To me the song is clearly about heroin addiction. Myself being a former addict can relate to this song entirely. The part about counting the hours of the day and "the light turns off inside your heart can you remember what its like to care" is the part leading up to the addiction and is what made you turn to using. "give me the drug keep me alive" is about how you literally need the drug in your system to function once you become dependant on it. You need to use it or you become as physically and mentally sick as the body can possibly get I. E "knees are weak, hands are shaking, i cant breath". Then "the grip loosens but it never breaks" is saying how you can try to quit hundreds of times but always end up relapsing. . "we carry nothing but a name you will forsake" = junky. And the part about "you words are always there to break my fall in them i find the comfort to see through it all" is reffering to the mentality of a junky being dependant on the security and sense of well being the drug gives them to deal with everyday life. But at the same time the relationship a user has with a substance mirrors the unhealthy/dependant relationsships people have with humans as well. So it could be about the concept as a whole. Either way one of my favorite songs.