There is compelling evidence from placebo-controlled studies that lithium augmentation is an effective strategy in the acute and continuation treatment of refractory unipolar major depression. Authors prospectively investigated the 1-year outcome of 22 subjects diagnosed with unipolar major depression who had participated in a 4-month placebo-controlled, double-blind continuation study of lithium augmentation without relapse. At the end of the double-blind phase, the blinded medication (lithium in 14 patients, placebo in 8 patients) was tapered off over a 1-week period, while the antidepressant was continued at the same dosage for another 4 weeks. Subsequently, the antidepressant was gradually discontinued over a 4-week period. Clinical status was assessed at regular follow-up visits. During the open 6-month follow-up period, seven subjects suffered an affective recurrence, five of whom had received lithium during the placebo-controlled, double-blind phase of the study. Study data suggest that active medication should be maintained for at least 1 year after successful lithium augmentation in patients with unipolar major depressive disorder.