Lyric discussion by Helj 

Cover art for Come Back Down lyrics by Toad the Wet Sprocket

This song is definitely about drug addiction, and the things people will do for a hit. By the sounds of the lyrics, this is probably a fairly hardcore drug - not something like booze or weed. More like pain killers, heroin, or even crack. Something that will come back in 2 hours is usually pretty hardcore.

Finally, it's possible that the author isn't the singer, but this might be the story of someone the guys in the band knew that did have a drug problem.