What psychological and emotional damage is there to a 4 month old separated from its mother for no reason my ex has our son wont give him back hes been away from me for a week and hes never ever been away from me since birth.

There . There is not enough contextual information to make a definitive comment. It is clear, however, that in the absence of judicial rulings regarding custody or visitation, if the mother and biological father are not willing or capable of communicating in a reasonable manner or can not reach some form of agreement regarding the care and custody of the infant son, that this is not a good thing. If the parents have an unhealthy relationship or they fight over their child, it is likely to negatively impact the child.