
Major depressive disorder affects over 280 million people globally and is a leading cause of disability-adjusted life-years. First-line pharmacotherapy with SSRIs and SNRIs combined with psychotherapy is established, while treatment-resistant depression has driven innovation, including ketamine/esketamine nasal spray, psilocybin-assisted therapy, and neuromodulation techniques. Biomarker-guided patient stratification and personalised treatment selection represent the frontier of psychiatric care.
