"The length of this review, necessitated by the steady growth in the number of indications for the potential therapeutic use of cannabinoid-related medications, is a clear sign of the emerging importance of this field. This is further underlined by the quantity of articles in the public database dealing with the biology of cannabinoids, which numbered ~200 to 300/year throughout the 1970s to reach an astonishing 5900 in 2004. The growing interest in the underlying science has been matched by a growth in the number of cannabinoid drugs in pharmaceutical development from two in 1995 to 27 in 2004, with the most actively pursued therapeutic targets being pain, obesity, and multiple sclerosis (Hensen, 2005)."

Source

Pacher, Pal; Batkai, Sandor; and Kunos, George, "The Endocannabinoid System as an Emerging Target of Pharmacotherapy," Pharmacological Reviews (Bethesda, MD: American Society for Pharmacology and Experimental Therapeutics, September 2006), Vol. 58, No. 3. p. 441.
http://pharmrev.aspetjournalsā€¦