The clinical usefulness of lithium as an antidepressant.

Much attention has been directed toward the use of lithium in bipolar depressive illness (manic-depressive illness), but fewer studies have evaluated lithium's efficacy in unipolar depressive disorders. This paper critically reviews the literature dealing with the use of lithium for the treatment of acute unipolar depression as well as for prophylaxis against future depressive episodes. Differences in study design, entry criteria, serum lithium level, dose, patient population, and diagnosis are highlighted; these variations help explain some of the controversy surrounding the use of lithium in unipolar depression. The available information indicates that lithium should be seriously considered as an effective alternative for the treatment of unipolar depression when other antidepressant medications are ineffective or contraindicated.