just google "rat park" there's a ton of info out there and of course some of it's divisive. i don't want to link something that props one side of the argument over the other.
like i said earlier, it's not a perfect solution, there's obviously more going on with addiction because there are PLENTY of people who never touch drugs until they get hooked on pain killers after a legitimate injury. but, the other side of the argument (as grim as it is) is that insurance companies wouldn't cover pain killers if the likelihood of someone becoming an addict was too high, they wouldn't risk the lawsuit. so while they are plenty of people abusing pain killers, it's a small enough percentage that insurance companies don't care.
either way, the bottom line is that happy, healthy, well adjusted people rarely, if ever, do drugs. if drugs make you feel good, but you already feel good, what's the point? you'd only see the negative consequences. but if you feel miserable and hate life, all the negative consequences from drugs don't matter because it's just more garbage on the pile.
i'm oversimplifying the situation, i know, but there you go