About half of Americans believe that marijuana should be legalized, when questioned during an October Gallup poll. This is the highest percentage since Gallup started asking the question in 1969.


Marijuana comes from the cannabis plant and is used as a psychoactive drug and for medical purposes. However, according to the National Institute on Drug Abuse's informational website, "Marijuana is the most commonly abused illicit drug in the United States."


The poll relied on telephone interviews with 1,005 adults ages 18 and over from Oct. 6 through Oct. 9. Fifty percent of those polled indicated that they support legalizing marijuana, while 46 percent do not, and 3 percent have no opinion on the subject.


The lowest support for legalization came from those 65 and older, only 31 percent of whom support blanket marijuana legalization. Liberals are twice as likely (at a high of 69 percent) to support legalization as conservatives (at 34 percent), and men are also more for legalization than women. [Trippy Tales: The History of 8 Hallucinogens]


Increasing acceptance

Results from the same poll taken last year revealed 46 percent of Americans supported legalization and 50 percent didn't. Until the 1990s, less than 20 percent of the American population answered the question "Do you think the use of marijuana should be made legal, or not?" with a no. Since then the percentage of Americans who support legalizing its use has increased about 10 percent every decade.


The increase in acceptance of the drug is probably linked to its increasing proliferation, say Gallup officials. Since 1997 the number of 12th graders who have used marijuana  has hovered between 45 and 49 percent. This age group, 18 to 29, is highly supportive of blanket marijuana legalization, with 62 percent of them saying it should be legal.


It also quotes the National Survey on Drug Use and Health from 2009, which states that "16.7 million Americans aged 12 or older used marijuana at least once in the month prior to being surveyed, an increase over the rates reported in all years between 2002 and 2008."


Medical marijuana

Marijuana is currently legal for "medical use" in 17 U.S. states, including California, Arizona and Maine, as well as in neighboring Canada. Medical uses include the treatment of glaucoma, nausea, headache, lack of appetite and pain.


Patients need to obtain a prescription for the drug from their doctors and buy the drug from "dispensaries." Since marijuana is still illegal under federal law, these dispensaries are often raided by federal law enforcement. A Gallup survey in 2010 asking specifically about marijuana legality for prescription use found that 70 percent of Americans favored its use to reduce "pain and suffering."


The Gallup poll was published online at Gallup.com on Monday.


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