Psychosis and water intoxication.

Three cases of psychosis, polydipsia, and water intoxication are presented as examples of a syndrome that is potentially unrecognized in psychiatric settings. Diagnostic and etiologic considerations, with particular attention to the syndrome of inappropriate antidiuretic hormone secretion (SIADH), are discussed through a review of relevant literature. A schema for a routine psychiatric evaluation is described that will minimize overlooking this association of psychosis and disturbed water balance.