Robert Leadbetter

Behavioral intervention to reduce water intake in the syndrome of psychosis, intermittent hyponatremia, and polydipsia

We describe a non-intensive behavioral intervention using an A-B design with extended follow-up on an open psychiatric unit to reduce water intake in a 52-year-old man with the syndrome of psychosis, intermittent hyponatremia, and polydipsia. A reinforcement schedule contingent upon weight gain secondary to water intake was employed. Mean diurnal weight gain was 7.1 pounds during a 23-week baseline which dropped to 4.1 pounds following 23 weeks of treatment and at a 1-year follow-up. Estimated fluid consumption dropped from 10 liters to 4 liters daily and incidents of hyponatremia decreased by 62%.

Development and validation of a behavioral observation measure for the syndrome of psychosis, intermittent hyponatremia, and polydipsia

A behavioral observation scale (Virginia Polydipsia Scale; VPS) for monitoring drinking patterns was developed and its reliability tested during 25 hours of tandem ratings among six patients with the syndrome of psychosis, intermittent hyponatremia, and polydipsia (PIPS). These ratings were compared to those collected from a control group of six psychiatric inpatients who were similarly observed for 25 hours. The scale was subsequently used to assess day-long drinking in a single PIPS patient. Results demonstrated that the VPS can be reliably administered by trained raters and that it clearly differentiates the drinking patterns of PIPS patients from controls. In addition, our findings highlight associations among drinking behaviors, psychiatric functioning and low serum sodium concentration. On balance, these results support using observational measures of drinking behaviors in future studies of PIPS patients.