The science on marijuana is settled. The assertions that continue to be made linking marijuana use to serious drug addiction by officials like Michele Leonhart, the former administrator of the Drug Enforcement Administration, are contradicted by facts.
Many promote myths about marijuana to justify the use of law enforcement and the testing of people for public benefits, jobs and exclusion from housing.
But since the science is settled, the question we should be unpacking is why do some people persist in promoting messages known to be false, as was done by Gov. Chris Christie of New Jersey during his failed bid for president? Why are we still not discussing the evidence: that the real gateways to addiction are poverty, trauma, mental health problems and the effects of criminalization and stigma?
There are many who have economic and political interests in promoting the myths that surround marijuana, none of which have to do with public health or safety. These myths about marijuana justify the use of law enforcement as the principal method to control its use, which is why more than half of all drug arrests annually are for possession of small amounts of marijuana. The myth justifies the use of drug testing of people applying for public benefits or almost any job and the exclusion of otherwise deserving people from needed public housing. The income generated for the companies that create drug tests or that privatize prisons is well-documented. Criminalizing people is a cash cow.
The majority of people who use marijuana (and most illicit drugs) do so in nonproblematic ways. Legalizing it protects their ability to do so without fear of punishment. And for those who develop a substance dependency, marijuana regulation will generate revenue to support drug treatment for those who need and want it. source: http://www.nytimes.com/roomfordebate/2016/04/26/is-marijuana-a-gateway-drug/look-at-the-real-gateways-to-drug-addiction