Rapastinel Trifluoroacetate is primarily researched for its potential in treating major depressive disorder (MDD). It functions as an NMDA receptor modulator, targeting the glycine site on NMDA receptors to enhance glutamatergic signaling in the brain, which plays a key role in mood regulation. This compound is being explored as a rapid-acting antidepressant, offering relief from depressive symptoms within hours or days, unlike traditional antidepressants that may take weeks to show effects. Its unique mechanism of action could provide a breakthrough for patients with treatment-resistant depression or those in urgent need of symptom alleviation. Clinical trials have evaluated its efficacy and safety, though development has been discontinued; it remains available for research purposes in mental health treatment.