Efficacy of the current antidepressants: the role of bupropion

Abstract

The serendipitous discovery of the precursors of two of the major contemporary antidepressant families during the late 1950's, iproniazid for the monoamine oxidase inhibitors (MAOI) and imipramine for the tricyclic antidepressants (TCA), has guided the subsequent development of numerous antidepressant drugs. For decades, known differences among these agents have, generally, been limited to aspects of safety and tolerability. This, in part, has been due to the fact that most antidepressant comparator trials, while adequately powered to show large efficacy differences, are not large enough to detect more subtle differences in efficacy that may exist among common, first-line antidepressant drugs including the selective serotonin reuptake inhibitors (SSRIs), serotonin- norepinephrine reuptake inhibitors (SNRIs), and the norepinephrine-dopamine reuptake inhibitor (NDRI) bupropion. This limitation could be overcome by combining data from individual trials with the use of pooled analyses and meta-analyses. In fact, the progressive accumulation of data from randomized, double-blind, antidepressant-comparator trials in major depressive disorder (MDD) has now made it possible to examine for potential differences among antidepressant agents. In the following review, we will briefly present an overview of such meta and pooled analyses of antidepressants in MDD, followed by a more focused description of studies focusing on describing the relative (to other newer antidepressants) efficacy of the NDRI bupropion in MDD which as recently approved in Spain for the treatment of MDD.