New onset of neuropsychiatric symptoms in the elderly: possible primary hyperparathyroidism.

Primary hyperparathyroidism is a disorder of calcium homeostasis that occurs most commonly in older adults. Resultant hypercalcemia may be accompanied by neuropsychiatric symptoms, ranging from mild depression and cognitive changes to extreme agitation and psychosis. Surgical intervention almost invariably reverses these symptoms. The authors reviewed the importance of considering this diagnosis in the setting of neuropsychiatric symptoms in the elderly and reported on a 63-year-old man with mild hypercalcemia and a new onset of psychosis.