If you are an alcoholic, there is no gamble, you will ruin your life and lives of people around you and die early and most probably miserably, period. Same with say smoking cigarettes, still a popular addiction of poorer folks all around the world.

It goes much deeper - children of drug abusers, be it legal or illegal, tend to very closely repeat their parent's mistakes also in this aspect, vicious circle that takes a strong personality and probably some luck to step out of. I consider it an utter failure as a parent, no nicer way around this.