Three cases of folie à deux are presented to demonstrate that the process develops in the prepsychotic relationship and that the primary partner is strongly

dependent on the secondary partner. The primary partner begins to feel that the secondary partner is taking advantage of his dependent needs and becomes increasingly angry. He then has to defend against the hostility to protect the relationship. This is done by projecting the hostility and results in paranoid delusions which he insists that the secondary partner accept. When the secondary partner at first refuses, the primary partner becomes more directly hostile. The ensuing anxiety forces the secondary partner to accept the delusions.