Self-induced water intoxication in schizophrenic patients.

The authors report on 21 cases of self-induced water intoxication and cite 25 others in the literature. Three of their patients demonstrated at least temporary inappropriate antidiuretic hormone secretion, 3 were receiving a diuretic, and the other 15 appeared to have "pure" water intoxication. Fifteen patients were receiving a psychotropic medication. Self-induced water intoxication appears to be more common in schizophrenic patients than is generally realized and should be suspected in any schizophrenic patient who develops convulsions or coma. Hyperdopaminergic CNS activity may be involved, and the authors suggest a possible mechanism similar to that for tardive dyskinesia.