Lithium carbonate and affective disorders. V: A double-blind study of prophylaxis of depression in bipolar illness.

The efficacy of lithium carbonate as a prophylactic drug against depression in bipolar manic depressive patients was assessed through a double-blind, placebo-controlled study of patients who had histories of recurrent depressions and hypomanias ("bipolar II"). The results revealed that treatment with lithium carbonate resulted in a reduction in the frequency of depressive attacks was observed with lithium carbonate treatment during the study (mean length of study, approximately 16 months), although there was a suggestion that the depressive attacks that occurred during treatment with lithium carbonate might be less severe than with placebo treatment.