Yeah, look at the Kennedys
That failure for a person to control his urges and give in to an addiction impacts almost all families, even those that are viewed by the larger community as the most respectable families.
The Kennedy Family, the Osmond Family, the Bush Family and the Limbaugh Family and most likely the family of most people that read this post.
The answer lies in self control. Teaching our children and teaching ourselves that simply because you want to, you do not have to take that sip, take that toke, take that snort, take that needle or take that crack pipe in your hand.