I too disagree that marijuana use necessarily leads to heroin addiction. The extant research simply does not support this. Even on an anecdotal basis, this is very flawed logic. I realize the scourge of heroin addiction must be very difficult for those who have experiences it in themselves or loved ones firsthand, but that is no reason to demonize a substance which, as has been pointed out here, is regularly enjoyed by many, many, many intelligent, educated and productive members of society, and at no detriment to their health or social interactions.

If you're going to blame cannabis for being the "gateway drug"   that leads to heroin addiction, you may as well blame nicotine, caffeine, sugar and alcohol, too; ALL of which are physically addictive. Marijuana does not cause physical addiction, nor does stopping its use cause 'withdrawal' symptoms.

Please don't call people uninformed or 'dim' unless you have actually bothered to read the scientific literature yourself, GUEST.