Sherlock Holmes as Necessary Madman: The Plot Thickens

Sherlock Holmes: Master of deduction or self destructive drug addict? Perhaps Conan Doyle's infamous sleuth owes his phenomenal powers of detection to his own personality flaws that seem to balance his character over a threshold of insanity during his crime solving sprees. While the character of Holmes could be profiled as a unique genius with an admirable work ethic and profound amount of knowledge in an abundant array of relevant subjects to his detective work, a more thorough psychoanalysis might yield that he is masochistic, depressed, obsessive compulsive, and a junkie. Why is Doyle's prototypical detective figure designed in such an unbalanced way? What does the seemingly paradoxical personality of Holmes add to the visual politics that are so prevalent in detective fiction? How do Holmes' weaknesses and derangements compliment and elevate him in an arena of ratiocination and how does he compare to other models of the detective?