Really? Explain.
The only things that can effectively ruin peoples like that are not their own fault are external events that are outside of their control.
If a tornado rips up your house, it can ruin your life. But it's not your fault.
If you get laid off because your emplorer is no longer making enough money to pay you, it can ruin your life. Not your fault though.
No thing that you, yourself, control, can be blamed for the problems caused by said thing. If you swing a hammer, miss the nail and hit your finger, you have no one to blame but yourself. Same goes for anything else in life that is a result of your own decision making.
Even when it comes to drug abuse, unless someone points a gun to your head and makes you take that first hit or that you were lied to about what you were taking (which is unlikely with the proliferation of information about drug addiction), it's no one's fault but your own.
/side rant
Why teenagers these days ever start smoking now is beyond me. You've got to be dumb as a doorknob to start smoking in the 21st century.
/end side rant
That's all I have to say on it.