Cannabis has been used as a medicine some 5,000 years, dating back to ancient China. The practice continued through to the 19th and 20th centuries; in fact, between 1840 and 1900, more than 100 papers on the topic were published in medical journals. Known as Indian hemp in those days, it was cited as an appetite stimulant, muscle relaxant, analgesic, hypnotic, anticonvulsant and treatment for migraine and opium addiction.