Oh Please the old gateway drug arguement. If that is your arguement then the real gteway drugs such as cigarettes adn alcohol should be first sicne they are typically what people who are addicts will reach for first.
http://www.marijuanaaddiction.info/news-left.htm?aid=49
Young people who smoke marijuana are two to five times more likely to move on to harder drugs. That is the formal opinion of researchers, who published their conclusions from a recent study in the Journal of the American Medical Association (JAMA).
It is also the informal conclusion of two recent high school graduates who talked with Family News in Focus. The two, who asked that their names remain anonymous, said they no longer smoke marijuana, but that most of the kids they smoked pot with in high school went on to harder drugs and aren't able to hold jobs.
"I realized how bad it disappointed my parents," she said. "My dad cried and so I stopped."
The JAMA study followed 311 sets of identical twins; one smoked pot while the other did not. Twins were chosen to help rule out a genetic or social explanation for the gateway effect. Almost half of the young people who started smoking marijuana before 17 went on to use harder drugs later in life. The study is the latest to suggest the link between marijuana and other drugs like cocaine and heroin. However, Howard Simon, of the Partnership for a Drug-Free America, said regardless of the evidence some still dispute the findings.
http://www.columbia.edu/cu/record/archives/vol20/vol20_iss10/record2010.24.html
Children who use marijuana are 85 times more likely to use cocaine than non-marijuana users.
Adults who used marijuana as children are 17 times more likely to be regular cocaine users.