Clinical implications of research on the mechanism of action of lithium.

Lithium is a unique drug in its clinical profile in psychiatry. Lithium has numerous biochemical effects, but none has yet been proven to be its mode of therapeutic action. Inhibition of noradrenaline-sensitive adenylate cyclase is reviewed as the only biochemical effect of lithium shown to occur in both animals and man at therapeutic lithium concentrations. A tetracycline antibiotic, demeclocycline, also blocks noradrenaline-sensitive adenylate cyclase. A clinical trial of demeclocycline in mania would provide a test of the adenylate cyclase theory of lithium action.