Association of nonsuppression of cortisol on the DST with primary polydipsia in chronic schizophrenia

Thirteen polydipsic and 40 nonpolydipsic chronic schizophrenic patients received the dexamethasone suppression test while stabilized on psychotropic medication regimens. Thirty-eight percent (N = 5) of those with polydipsia but only 5% (N = 2) of those without polydipsia were nonsuppressors of cortisol (i.e., had an abnormal response). It is suggested that hippocampal dysfunction could cause both polydipsia and cortisol dysregulation in these patients.