To investigate the pathogenesis of water intoxication in psychotic
disorders, a standard water load test was given to 23 unmedicated patients
with schizophrenic or schizoaffective disorders. Levels of plasma arginine
vasopressin were measured concurrently. Compared with 28 healthy
volunteers, the psychotic patients had significantly smaller cumulative
urine output and higher minimum urine osmolalities. Patients whose current
illness had lasted less than 24 weeks exhibited the most severe
antidiuretic state and also had the highest plasma arginine vasopressin
levels. Water intoxication in acute exacerbations of psychosis may develop
as a result of impaired excretory mechanisms.Abstract Teaser