They are helplessly concerned about two generations of children. It doesn't stop there either. The strain continues on to spread into friendships as well. Parents confidence in their parenting skills plummet. They begin questioning everything they have done raising this child while looking for the reasons this may be occurring.
Tempers can shorten and frustrations grow tall.
Everyone is scared. Often blaming occurs between the parents. The marriage is now entering one of it's greatest challenges. Those in the immediate family at least, begin to utilize every coping skill they have. Hopefully they will work, but no one really knows.