i was reading some interviews from the 70's ("bowie in his own words" interview compilation book) and bowie admitted he first did cocaine in 1965! In an interview with a british artist in the summer of 2001 DB said "S2S was a drug album, NLMD was a drug album". IN the Buckley book there is a bowie quote from 92 saying "it's been 2 years since i last did any kind of drug"
The topic came up in a visconti interview(uncut magazine from last fall?) that bowie is only cigarrettes and Coffee now.
Also keep in mind that Bowie did coke in order to work harder and not to escape. He didn't hide in his house only doing coke like phil spector, brian wilson, elton in the 80's, sly stone and a whole slew of other people.
He's always been a bit nuts; I mean, look at his family, for heaven's sakes!! (I'm referring to Peggy's family, especially her sisters.)
A lot of Bowie's earlier stuff is basically him hiding behind his fear of growing insane; for example, 'Alladin Sane' - if my memory serves me correctly, that song had a lot to do with himself and his half brother, Terry Burns.....
"You all want my money, you leeches!" - David Bowie
Forget about the baby!