About two-thirds of depressed patients respond to a standard course of serotonin specific reuptake inhibitor (SSRI's) within 3-4 weeks. While some clinicians advise continued watchful waiting after this time or switch to a different reuptake-blocker based antidepressant, result of such conservative strategies are usually disappointing. For severe depression electroconvulsive therapy (ECT) is an option and for atypical depressions monoamine oxide inhibitors (MAO) inhibitors often give relief at this point. A unique strategy with both theoretical and practical implications is lithium augmentation (Fava et al, 1994). Addition of lithium to SSRI failures at 3-4 weeks is consistently and sometimes dramatically found to be helpful. This is considered true even by those authors who advocate use of lithium under usual circumstances only in bipolar patients.