I think it's a bit petty that people blame the drugs rather than the fact they lack self control.
That's like saying "I didn't shoot and kill that man, the gun did."
Same thing as when people blame god, looking for something external to blame because they can't take responsibility for their own actions. Drugs aren't for everyone, if you're unable to control yourself while doing whatever it is that you're doing, don't do it. If you continue to do these things, while they "destroy your life," then that is all on you, no one else. (because you could have stopped, you knew that your life was being destroyed, it doesn't just happen over night.)
We don't need laws on stuff like this, it should be simple: "Like it? Do it... Don't like it? Don't do it." Whatever happens past that point is on you. You are human, you have the capacity for critical thinking, utilize it to make the correct decisions.