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.