In this article the problem of the symbiotic relationship between mother and child is discussed. With case illustrations, the authors attempt to demonstrate the special quality of the symbiotic relationship when the process of separation-individuation is arrested. They suggest that the ambivalent quality of the bond is expressed in oversensitivity, anxiety, exaggerated worry, and mutual emotional penetration between the mother and the child. In many instances there were no early symptoms indicating this lack of separation-individuation. They became manifest only at a later stage during psychotic breakdown.