Where did the term 'junkie' originate?

According to wiki.answers, the term originated to refer to people who were hooked on "junk", a nickname for heroin. It has now spread into the vernacular to refer to those avidly interested in other areas, such as a "sports junkie" or a "political junkie."
http://wiki.answers.com/Q/What_is_the_origin_of_the_word_junkie

junkie (n.) "drug addict", 1923, from junk (n.1) in the narcotics sense + -y (3). Junker in the same sense is recorded from 1922. Junk for "narcotic" is older.

http://www.etymonline.com/index.php?term=junkie&allowed_in_frame=0

junk (n.1) "worthless stuff", mid-14c., junke "old cable or rope" (nautical), of uncertain origin, perhaps from Old French junc "rush, reed," also used figuratively as a type of something of little value, from Latin iuncus "rush, reed" (but OED finds "no evidence of connexion"). Nautical use extended to "old refuse from boats and ships" (1842), then to "old or discarded articles of any kind" (1884).

http://www.etymonline.com/index.php?term=junk&allowed_in_frame=0