Characteristic changes in psychiatric symptoms, cortisol and melatonin but not prolactin in primary hyperparathyroidism

Psychiatric symptoms in primary hyperparathyroidism (PHPT) are usually characterized as depressive. In this study 13 patients with PHPT and six control patients with atoxic nodular goiter underwent psychiatric ratings with the comprehensive psychopathological rating scale (CPRS) the day before surgery. The 21 items in this scale were grouped into clusters. The ratings were repeated after successful removal of a parathyroid adenoma. Diurnal serum concentrations of cortisol, melatonin and prolactin were studied pre- and postoperatively in eight of the patients. Patients with PHPT had significantly higher CPRS total scores, 8.5 +/- 1.3, compared with goiter controls, 1.9 +/- 0.8, and showed a significant improvement of psychiatric symptoms after excision of the parathyroid adenoma, to 3.3 +/- 0.9. The preoperative diurnal and peak levels of cortisol and melatonin were higher (P less than 0.05) than after surgery. Serum melatonin fell to levels lower than those in healthy controls. Correlations were found between some clusters or items and cortisol or melatonin. Serum prolactin levels were normal and unaltered by parathyroid surgery. It is concluded that patients with PHPT show well defined psychiatric symptoms many of which are correlated to alterations in serum cortisol and melatonin accompanying PHPT. The improvement of symptoms seen after successful surgery further suggests that PHPT is associated with a specific psychiatric disorder similar to but distinguishable from major depressive disorder.