First thing would be to have your doctor evaluate him to make sure he doesnt have the same problems as his mother. If that is not the case, remember he is under a lot of stress too, since you said you are in the process of adopting him. He is probably scared and reverting back slightly to a younger age. It happens in a lot of casing of stress, new home, new baby, new situation. Chances are once his life becomes more stable and constant, then it will come quickly. If it is stress related, there isnt much you can do except be consistant. I hope for the best for all of you, Good Luck!