Léo Trézenik's The Confession of a Madman, originally published in 1890 and here presented in English for the first time in a translation by Brian Stableford, is one of the most substantial contributions to a subgenre of Romantic fiction that details delusional fantasies: accounts of strange experiences that could be interpreted as supernatural hauntings or as symptoms of mental derangement.

Trézenik (1855-1902), who played a significant role in the Decadent Movement, was a former medical student, and might himself have wondered whether he might have been in danger of going mad, those associated with the Movement being routinely accused of insanity by hostile critics. In much the same spirit that they accepted and twisted the charge of "decadence," of course, some of them were not entirely displeased by the questioning of their sanity, and were eager to treat such suspicions as evidence of their genius-and the present novel certainly shows ample evidence of this latter property on the part of its author.

The protagonist of The Confession of a Madman never mentions drug use, but the epilogue relating the "factual backcloth" to his delusions is careful to do so, in order to permit the interpretation that the fashionable opiate of the day-morphine-might have made a considerable contribution to the notional narrator's state of mind.