A 68-year-old man was hospitalized in August, 1990 with general malaise, loss of energy, poor appetite and severe depression. He had experienced depressed moods, markedly diminished interest, feelings of worthlessness, diminished ability to think, general malaise and muscle weakness beginning in November, 1989. He was treated for depression at another hospital until his emergent admission to our hospital because of difficulty in walking. Laboratory studies disclosed hyponatremia, low plasma ACTH level (4.2 pmol/L), and a low cortisol level (27.6 nmol/L). Rapid ACTH test elicited an increase in serum cortisol from 75.6 nmol/L to 361.2 nmol/L at 30 min. Ovine corticotropin releasing hormone (CRH) did not stimulate secretion of either ACTH or cortisol. Human growth hormone releasing hormone (GRH) together with thyrotropin releasing hormone (TRH) elicited a normal response of TSH and low responses of GH and PRL. The patient's serum autoantibodies to anterior pituitary cell membranes using GH3 rat pituitary cells and AtT-20 mouse pituitary cells were positive. On the basis of these data, the diagnosis of selective ACTH, GH and PRL deficiency was made and thought to have been caused by lymphocytic adenohypophysitis. Following cortisol replacement therapy, he quickly regained his appetite and was restored to a normal mental state of being.