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MPP Report: Does Prohibition of Marijuana for Adults Curb Use by Adolescents?

MPP's December 2006 report examines whether current marijuana laws effectively deter marijuana use by young people. Among the major findings:
Marijuana prohibition has not prevented a dramatic increase in marijuana use by teenagers. In fact, the overall rate of marijuana use in the U.S. has risen by roughly 4,000% since marijuana was first outlawed.
Independent studies by RAND Europe and the U.S. National Research Council have reported that marijuana prohibition appears to have little or no impact on rates of use.
Since Britain ended most marijuana possession arrests in 2004, the rate of marijuana use by 16-to-19-year-olds has dropped.
In the U.S., rates of teen marijuana use in states that have decriminalized adult marijuana possession are statistically equal to rates in those that have retained criminal penalties.
In the Netherlands, where adults have been allowed to possess and purchase small amounts of marijuana since 1976, the rate of marijuana use by adults and teens is lower than the U.S., and teen use of cocaine and amphetamines is far lower than in the U.S.