The assessment and treatment of water imbalance in patients with psychosis.

Polydipsia and episodic life-threatening water intoxication remain important clinical problems for a significant portion of persons with schizophrenia. The disorders are associated with increased morbidity and mortality from a number of causes. With a basic understanding of the pathophysiology, one can easily diagnose and assess the clinical conditions. We review here the scope and pathophysiology of disordered water imbalance, including both primary and secondary polydipsia and hyponatremia. Reversible factors and possible interventions are reviewed. Treatment options for preventing water intoxication have expanded from discontinuation of offending agents, targeted fluid restriction, and clozapine therapy to the addition of oral vasopressin antagonists. The latter, however, are extremely potent and must be carefully monitored.