There's lots that I have learned over the past years about addicts - there are some excellent scientific studies out there, for example, that show how the pleasure/reward systems differ between people and this can have a bearing on how people get addicted and how it is more difficult for some to stop than others. That's how drugs like antabuse got developed. And there will be more being done all the time because there is money in finding a drug based "cure". Heck there is money in non-drug based "cures" too.
But unless the desire to stop is greater than the desire to continue, it all come to naught, doesn't it? As a society, we can't find a way to stop illegal drug use, let alone that of a drug that is legal.