Seltorexant, a potent, selective orexin-2 receptor antagonist, improved symptoms of major depressive disorder (MDD) and insomnia in a phase III trial. The study drug, when combined with current antidepressant treatment, showed a significant reduction in Montgomery-Åsberg Depression Rating Scale (MADRS) total score compared to placebo. Seltorexant is unique as it targets only OX2 receptors, potentially filling an unmet need for new therapies for MDD and insomnia.