Well you don't see people calling tobacco a gate way drug so there must be a reason that they call marijuana a gateway drug. Perhaps because statistics show it to be true?
Link
1) this is a prime example of the telephone game mucking up data as it gets passed along (or it may have been a deliberate misrepresentation)
edit: I just noticed the deliberate misrepresentation, they failed to mention that the risk is also 104 times greater for those who use alcohol, and for those who use cigarettes, since you have to use all 3 to fall into this category
Compared with people who used only one gateway drug... ...adults are 104 times--more likely to use cocaine.
that is a disgusting manipulation of data there. -government sponsored anti drug message manipulation at its finest right there. /edit.
2) correlation =/= causation.
Your sources source is here:
NIDA - Publications - Marijuana: Facts Parents Need to Know - Text Only
This document no longer contains the "104 times more likely" claim, for a couple of reasons. It is outdated, inaccurate, and misrepresented.
The "104 times as likely" figure came from a misrepresentation of a
1994 CASA report.
The Center on Addiction and Substance Abuse at Columbia (CASA) released a study Oct. 27 showing that children (12 to 17 years old) who use gateway drugs--tobacco, alcohol and marijuana--are up to 266 times--and adults who use such drugs are up to 323 times--more likely to use cocaine than those who don't use any gateway drugs. Compared with people who used only one gateway drug, children who used all three are 77 times--and adults are 104 times--more likely to use cocaine.
http://www.columbia.edu/cu/record/archives/vol20/vol20_iss10/record2010.24.html
Someone was not very good at the telephone game, the alcohol and tobacco references somehow got dropped on their way into being widespread propaganda.
This CASA report was relied on heavily and extensively, and was why the ONDCP pushed the gateway hypothesis during the mid to late 90's, and made it an integral (but short lived) part of their strategy:
The National Drug Control Strategy for 1997 cites this (CASA) report multiple times, including this instance:
Of adults who use cocaine, 83 percent identify cigarettes as a gateway drug.]
IV. A Comprehensive Approach
Unfortunately (for the ONDCP, and their future reliance on the Gateway hypothesis) the only thing this paper demonstrated was correlation; however for the hypothesis to have merit it needed causation.
This is what led to such interest in supporting the gateway hypothesis in the ONDCP requested IOM paper I mentioned a few pages back.
The fear that marijuana use might cause, as opposed to merely precede, the use of drugs that are more harmful of great concern. Judging from comments submitted to the IOM study team, this appears to be an even greater concern than the harms directly related to marijuana itself.
http://www.debatepolitics.com/polls/62548-marijuana-helps-grow-brain-cells-10.html
They really, really wanted this theory to pan out. instead it got turned on its head.
one little sentence, and it was all but abandoned by the ONDCP, yet the legacy of their brief lived campaign lives on, here is the reality that blew up in their face - direct from the very paper they requested:
it is the legal status of marijuana that makes it a gateway drug.
Marijuana as Medicine - Assessing the Science Base - Institute of Medicine Report
And the gateway hypothesis lives on, despite the ad hoc fallacy (actually because of it, it is easy to assume that correlation does = causation)
