Diabetes insipidus is caused by a lack of antidiuretic hormone (ADH), also called vasopressin, which prevents dehydration, or the kidney's inability to respond to ADH. ADH enables the kidneys to retain water in the body. The hormone is produced in a region of the brain called the hypothalamus. It is stored and released from the pituitary gland, a small gland at the base of the brain. When diabetes insipidus is caused by a lack of ADH, it is called central diabetes insipidus.