Perhaps the finest writer ever to use speed systematically, however, was W. H. Auden. He swallowed Benzedrine every morning for twenty years, from 1938 onward, balancing its effect with the barbiturate Seconal when he wanted to sleep. (He also kept a glass of vodka by the bed, to swig if he woke up during the night.) He took a pragmatic attitude toward amphetamines, regarding them as a "labor-saving device" in the "mental kitchen," with the important proviso that "these mechanisms are very crude, liable to injure the cook, and constantly breaking down."
John Lanchester, "High Style," The New Yorker, January 6, 2003