I'm not sure, I agree it sounds like pop psych crap and you'll develop physical dependence of course, but I suspect there's a big difference between people who can pick up smoking weed on a weekly or monthly basis recreationally and people who find a need to be high every waking minute of their day. People who take to drinking a bottle of vodka for breakfast and those who keep it to the odd occasion. I don't see why we wouldn't see similar for other, even more physically addictive drugs.