Did he really do that many drugs?

I've been a long-term fan of Hunter S Thompson's writings, especially 'Fear and Loathing' and his collected works in 'The Great Shark Hunt'. He was certainly abosolutely right about a lot of stuff, especially when it came to nailing Nixon, long before Watergate. But did he really take the industrial qualtities of drugs and alcohol he claims to have done? And still write? If he did maybe he had a tremendous and patient editor or editors, able to lash his ramblings in to somehting representing sense.

Anyone got any insight in to what he did and indeed how he did it for so long? Or was there a considerable amount of ahem, exaggeration?