I would venture to say that when we allow our children the opportunity to struggle, and perhaps even fail, we also give them that chance to succeed by using their problem solving skills.  They build up their coping skills and have an early ownership of the feeling of success (and failure).

I strongly believe that the coping skills our children learn at a young age (when the stakes are low) will help them overcome bigger problems when they are older (when the stakes are high).  
​I believe that we need to teach our children that it's OK to fail.  We then need to teach them how to overcome that failure... and finally we teach them how to move on and past it.  When we do this,  we are teaching them the process of relying on themselves as opposed to outside forces (like drugs and alcohol) when they are older.  
It's OK to love them through the hard times, especially when they are young,  but try to step back when it's safe to let them figure things out for themselves.  If this is done properly when they are young (and the stakes are low) then the benefit of learned coping skills will be worth it.