The U.S. FDA has approved REXULTI® (brexpiprazole) as an adjunctive therapy for the treatment of adults with major depressive disorder (MDD) and as a treatment for adults with schizophrenia (SZ). RESULTI was discovered by Otsuka, a pharmaceutical company headquartered in Tokyo, Osaka and Naruto, Japan, and co-developed with Lundbeck, a pharmaceutical company headquartered in Copenhagen, Denmark. MDD is one of the most common psychiatric disorders in the world; and SZ is a chronic and severe mental disorder. Both mental diseases are debilitating and impose huge economic and societal cost. Despite of many anti-depressants and antipsychotics on the market, the efficacy is not ideal due to multi-factorial etiology, and relapse and medication-related comorbidities are major challenges in managing these mental illness. The approval of RESULTI is supported by four completed placebo-controlled clinical phase III trials in MDD and SZ patients. The approval of REXULTI will add another treatment option to the arsenal fighting these devastating mental illnesses.