Condition Direction Hormone Acromegaly overproduction growth hormone Cushing's disease overproduction adrenocorticotropic hormone Growth hormone deficiency underproduction growth hormone Syndrome of inappropriate antidiuretic hormone overproduction vasopressin Diabetes insipidus (can also be nephrogenic) underproduction vasopressin Sheehan syndrome underproduction any pituitary hormone Pickardt-Fahlbusch Syndrome underproduction any pituitary hormone, except prolactin, which is increased Hyperpituitarism (most commonly pituitary adenoma) overproduction any pituitary hormone Hypopituitarism underproduction any pituitary hormone