Lithium. Current status in psychiatric disorders.

Lithium is the recommended treatment for the prophylaxis of bipolar affective disorder. The drug is also effective in the prophylactic treatment of recurrent unipolar depression, although many psychiatrists prefer to use antidepressant drugs for this indication. The efficacy of lithium is well established in the short term treatment of mania, although neuroleptic drugs are required at the start of treatment for more severely disturbed patients. Lithium augmentation of antidepressant drugs is increasingly popular for the treatment of resistant depression. It is now common practice to maintain serum lithium concentrations in the range 0.5 to 0.8 mmol/L, which is generally as effective as higher concentrations while reducing the incidence of adverse effects and intoxication. Some individuals may nevertheless require higher serum concentrations. Most adverse effects such as tremor and gastrointestinal upset are usually minor and often transient. There is no good evidence of nephrotoxicity with long term treatment, but persistent polyuria can occur. Hypothyroidism, with or without goitre, can occur uncommonly during long term lithium therapy. Prescribers should be alert to, and patients should be educated about, the predisposing factors and early symptoms relating to lithium intoxication. Specialist mood disorder clinics can facilitate safer and more effective lithium treatment.