Marijuana, which comes from the hemp plant Cannabis sativa. Marijuana is the most commonly used illegal drug in the U.S. and the world, and was a well-established medicine until it was federally criminalized in 1937. A majority of Americans believe marijuana should be legally regulated. About 4% of American adults smoke pot at least once a year. Roughly 1% of adults abuse pot, and one in 300 have a pot addiction.
The rates of marijuana smoking in adults have remained stable since the 1990s. However, the rates of addiction to pot have risen significantly over that same period. And, according to recent government studies, as many as 30% of today's teenagers are smoking marijuana.

Legalizing marijuana

According to a Gallup poll, a clear majority of Americans favour legalizing marijuana for the very first time. In 2013, 58 percent of Americans stated the drug should be legalized, in stark contrast to 12 percent back in 1969 when Gallup first asked the question.
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