Why does the government already have a registered patent on cannabis as "antioxidants & neuroprotectants"?

[culley96]

http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/PTO/srchnum.htm&r=1&f=G&l=50&s1=6630507.PN.&OS=PN

[delron]

Usually in circumstances where the US government holds a patent it is because the "invention" was developed by a Federal employee as part of their job, or because the research was funded by the government for the purpose of making a new discovery that would lead to a patentable product. The link refers to a potential drug that could be used to treat Parkinson's disease.