Well lets see.. my brother...
Has been in jail a few times, was physically abusive to women, couldn't hold a job.. didn't care to hold a job.. stole from family.. ya know the "cool" stuff...
Then he got a job with my uncle where they had random drug screening.. he actually stopped.
Now .. he's married takes care of 2 kids STILL works that same job (when he's not laid off

) and is a very hard worker. He's still struggling to get by but at least he tries....
My cousin...

still on the stuff

Haven't seen him for > 4 years and dont' really care too.. he has 2 kids one I'm not even sure if he cares to meet. The other I'm not sure the last time he saw him. He kinda works when he's not in jail and last I knew he was a bit behind on child support.. suprising eh? (a bit behind being .. the entire life of the child... )
Can I attribute it solely to that stuff? No but a hell of a coincidence eh?