A genetic or acquired polyuric disorder caused by a deficiency of vasopressins secreted by the NEUROHYPOPHYSIS. Clinical signs include the excretion of large volumes of dilute urine; hypernatremia; thirst; and polydipsia. Etiologies include head TRAUMA; surgeries and diseases involving the hypothalamus and the pituitary gland. This disorder may also be caused by mutations of genes such as ARVP encoding vasopressin and its corresponding neurophysin (neurophysins).