Marijuana is a popular mood-altering drug. Also known casually as weed, pot, grass, herb, Mary Jane, or a variety of other slang terms, marijuana is a mixture of dried flowers, leaves, and stems of the Cannabis sativa. It is smoked in hand-rolled cigarettes and water pipes (bongs), and can also be used in teas and edibles (i.e., brownies, cookies, and candies). In terms of its popularity, the United Nations has declared marijuana the most used illicit drug in the world, with approximately 180 million users worldwide. When it comes to the subject of marijuana, however, a drug often used for its mental and physical effects, there are a series of concerns. The issues include potential health effects and addiction, medical marijuana, legalization, and the impact ...