Those with ADD, PLEASE help me understand the minimal responses

My husband (who has ADD) and I have a child with ADD.  My husband and I live in different states.  Whenever I email my husband once in awhile regarding our son's depression or problems with his ADD (which I am dealing with all by myself), a typical response from him is "that's too bad" or "poor thing".  That is all my husband will write back to me.  It happens all the time, so it's not a case of him being busy at work and not having time to respond more thoroughly.  It is so frustrating!!  Makes me feel like why do I even bother telling him.  Please help me understand this typical minimal response? Thank you.  I appreciate all thoughts on this behavior.