Dopamine supersensitivity, presumably playing a role in tardive
dyskinesia, has been implicated in the unexplained polydipsia occurring in
chronic psychiatric patients. To investigate this hypothesis, the authors
compared laboratory measurements indicating the fluid status of 65 patients
before and after the development of tardive dyskinesia. No evidence was
found that patients who develop tardive dyskinesia concurrently develop
abnormalities in fluid regulation.