That's very subjective. I know you're looking for precise answers, but I'm not sure there are precise answers. I think a parent should seek help when they feel that their child's level of frustration and the behavior their child is exhibiting is of concern to them and goes beyond what they can do to handle it well. I'm not sure that it helps anybody to say, "Here's when you should be concerned," because everyone has their own threshold. You should be concerned when you're concerned. You should seek out help when you feel like you need help.
What is the youngest age at which Plan B—the collaborative method—can start to show results?
Even when a child is born, the role of the adult in the child's life is to figure out what the child is trying to communicate when they're unhappy or frustrated and try to be responsive to that. Now, as children develop communication skills they are able to be involved in that process with words, and that makes it a little bit easier, but I think you are collaborating in some respects with your child in infancy. Because even in infancy kids are communicating to us, and even in infancy we are trying to be responsive to what they are communicating. And even in infancy we're trying to make sure the way we're responding addresses whatever's getting in their way. They're not able to use words yet, but they are communicating.
Read how one family has overcome their son's violent rage.