[Polydipsia: review of the literature]

Polydipsia, unrelated to organic polyuria is present in 20% of the patients hospitalised in psychiatry on a long term basis. It seems that about a third of them have presented at some point an episode of water intoxication. Most patients with psychogenic polydipsia excrete all the water they absorb. In a subgroup of them, at risk for water intoxication, the capacity to excrete water is deficient. This is usually due to an inappropriate secretion of antidiuretic hormone. The first two steps in the treatment of patients with psychogenic polydipsia consist in making the diagnosis and in evaluating the risk of water intoxication. To do this, one must monitor throughout the day their weight and the serum sodium plasma level if necessary, then reduce the risk factors and prescribe water restriction during the high risk periods. Behavioural therapy is sometimes used; prospects for chemotherapy are being studied. It is probable that there is not a single type of patient with psychogenic polydipsia but several subtypes, the etiology being multifactorial.