Self-induced water intoxication: a comparison of 34 cases with matched controls.

Of 2201 psychiatric patients in public facilities in a single metropolitan area evaluated for polydipsia, 34 (1.5%) were found to have a history of self-induced water intoxication. Among them, they had 101 episodes of water intoxication. Their mean age was 48.2 years, and they were predominantly white. Most had the primary diagnosis of schizophrenia. Compared with a matched control group, they had received more multiple courses of ECT but there were no significant differences in their use of psychotropic medications. Among nonpsychiatric medications, only phenytoin sodium and hydrochlorothiazide showed a trend toward significance.