In "The Seven-Per-Cent Solution", this literary character is treated by Sigmund Freud for drug addiction
Using a treatment consisting 
largely of hypnosis, Freud helps Holmes shake off his addiction and his 
delusions... [DOC] [TLE] Amazon.com: Customer Reviews: The Seven-Per-Cent Solution by ... [PAR] Sherlock Holmes has been my very favorite literary character for as long as i can 
.... woman also had a drug overuse problem and was treated by Freud.