Some kids go off the derech because their parents were at fault. Others do for reasons that have nothing to do with their parents.
My question is, what are you doing about your child who is addicted to drugs right now? Are you allowing him to waste his life away, or are you getting him help?
Probably not. But if any of these qs children had any emotional issues was it addressed. If you saw at some point your child was with a bad crowd MOVE if you have to.
I see many threads here about moving. You can't afford 5his neighborhood move out of town.... You can't afford boro park move to lakewood.... Neighbors and communities have a bigger impact on us, and our families than we might realize. Make sure you and your children are surrounded by good people and that you have good support system and a rav that is nonjudgmental for you and your family.