Renal function in chronic lithium-treated patients.

We investigated the renal function (urine volume, glomerular filtration rate, urinary osmolality and proteinuria) of 50 patients chronically treated with lithium carbonate for major affective disorder. No patient had any alteration in the parameters considered. No relationship was found between any of the parameters studied and duration of illness or lithium levels, both in serum and red blood cells. These results were confirmed by the administration of the DDAVP test to 10 patients of the original sample; no alteration of concentration ability was found. We suggest that the discrepancy between our findings and those of most authors was a result of the serum lithium level of our patient sample, which was lower than that usually used in other studies.