. . . . but I am constitutionally sensitive — nervous in a very unusual degree. I became insane, with long intervals of horrible sanity. During these fits of absolute unconsciousness, I drank — God only knows how often or how much. As a matter of course, my enemies referred the insanity to the drink rather than the drink to the insanity.
(From the introduction to The Fall of the House of Usher and Other Writings.)