Traditional guidelines call for treatment of major depression with a sequence of single antidepressants. Augmentation with a second agent generally only occurs when the first agent is well tolerated and when it also provides at least some symptomatic improvement on its own. Since this standard approach leads to low rates of attaining and sustaining remission by the first agent, with diminishing returns for each subsequent agent, there is growing dissatisfaction with this approach to the treatment of major depression. One new trend is to attempt to enhance the rates of sustained remission from a major depressive episode by combining two therapeutic agents from the very initiation of treatment of a major depressive episode.

Traditional treatment of major depression begins with a single “first line” antidepressant, and if it does not work or is not tolerated, trying another and then another. Unfortunately, this strategy results in disappointing remission rates for the first antidepressant (Figure 1), and disappointing rates of maintaining any improvement that is attained by this first agent because of high relapse rates over the next year despite continuing treatment with the first antidepressant (Figure 2A). And that is the good news. The bad news is that with each subsequent antidepressant treatment administered remission rates are progressively reduced (Figure 1). For those patients who do improve, they are progressively less likely to sustain their therapeutic gains despite continuing to take the drug that led to their initial improvement (Figure 2).