Lubazodone (developmental code names YM-992, YM-35995) is an experimental antidepressant which was under development by Yamanouchi for the treatment for major depressive disorder in the late 1990s and early 2000s but was never marketed. It acts as a serotonin reuptake inhibitor (K_i for SERTTooltip serotonin transporter = 21 nM) and 5-HT_2A receptor antagonist (K_i = 86 nM), and hence has the profile of a serotonin antagonist and reuptake inhibitor (SARI). The drug has good selectivity against a range of other monoamine receptors, with its next highest affinities being for the α₁-adrenergic receptor (K_i = 200 nM) and the 5-HT_2C receptor (K_i = 680 nM). Lubazodone is structurally related to trazodone and nefazodone, but is a stronger serotonin reuptake inhibitor and weaker as a 5-HT_2A receptor antagonist in comparison to them and is more balanced in its actions as a SARI. It reached phase II clinical trials for depression, but development was discontinued in 2001 reportedly due to the "erosion of the SSRITooltip selective serotonin reuptake inhibitor market in the United States".