In "The Seven-Per-Cent Solution", this literary character is treated by Sigmund Freud for drug addiction
... the 
Great Detective as a delusional addict and partners him with Sigmund Freud to... [DOC] [TLE] Amazon.com: Customer Reviews: The Seven-Per-Cent Solution [PAR] Sherlock Holmes has been my very favorite literary character for as long as i can 
... the very idea that Sherlock's infamous addiction to cocaine might get the best 
of him, ... (Sherlock's brother to lure him to Austria to be treated by Sigmund 
Freud.