The way my daughter's middle school health class classifies drugs is insane.
Marijuana is its own special category, but club drugs (which for some reason include date rape drugs), inhalants and steroids are all in a "miscellaneous" category together?
Also, note all the ridiculous drug propaganda lies.
I'd argue that if there is any gateway effect, it's solely related to the propaganda taught to the public that falls apart once you've actually tried some of them.
I don't think there's anything inherent about the drugs themselves that would drive you to try anything stronger. It's more that the misinformation makes people think "if they lied to me about this, what else were they lying about?" after trying something like weed and realizing it doesn't turn you into a psychopath or make you want to jump out of a window.
Not really true at all in Canada. Once again this is just the side effects of weed being illegal being mistaken for the fault of the substance when it's not.