Lithium-induced nephrogenic diabetes insipidus.

Two patients with severe lithium-induced nephrogenic diabetes insipidus are described. Although it is known lithium can cause diabetes insipidus, one should be especially alert in psychiatric patients, as the main defence mechanisms thirst and drinking behaviour may not function adequately in these patients. The major form of therapy in both patients consisted of drinking, a thiazide diuretic, as well as a protein and sodium restricted diet.