I think that it might be something useful for a child to know about how MI actually manifests itself. That they learn a useful lesson for life, and might become better and more understanding people as a result of that. That is of course, if a parent/caregiver does not abuse/ignore their needs as a result of MI, and then doesn't let the child know what is going on. All parents are bound to make some mistakes, no matter if they have an illness or not. In the case of my son, I have chosen to be as open as possible. One of the reasons is that he has inherited the gene for BP from me, and I want him to understand a lot about the illness in case he gets BP himself.