The landscape of modern neuropsychiatry is undergoing a profound paradigm shift. For decades, the dominant framework for treating Major Depressive Disorder (MDD) and Treatment-Resistant Depression (TRD) relied almost exclusively on the monoaminergic hypothesis. Traditional pharmacotherapies—such as Selective Serotonin Reuptake Inhibitors (SSRIs) and Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs)—attempt to increase ambient monoamine concentrations within the synaptic cleft. However, these conventional interventions are fundamentally limited by substantial systemic delays, often requiring weeks or months to demonstrate clinical efficacy, while yielding discouragingly low remission rates for severely afflicted populations.