Treatment-resistant depression affects many people with major depressive disorder who do not achieve remission with standard antidepressants. This review examines current and emerging strategies, including medication combinations, neuromodulation, and psychedelic-assisted therapies. Ketamine, esketamine, and psilocybin show promise for non-responders. Future approaches may repurpose drugs like lurasidone, pioglitazone, and minocycline for new mechanisms and better tolerability. A personalized, evidence-based, multidimensional treatment plan is emphasized to improve short-term response and long-term recovery.
Chronic pain is a widespread condition that often resists standard treatments like opioids, which carry risks of dependency and tolerance. Ketamine, a dissociative anesthetic, shows promise for managing several chronic pain types, including neuropathic pain, cancer-related pain, and complex regional pain syndrome. This review examines current evidence on ketamine's efficacy, mechanisms, clinical applications, safety, and limitations, drawing on articles from PubMed and Scopus.