The Use of Ketamine for Depression in Cancer Patients: A Systematic Review of Efficacy, Safety, and Clinical Applications

Depression is a common and serious concern in cancer patients, significantly impacting quality of life, treatment adherence, and overall prognosis. While traditional antidepressants often take weeks to exert therapeutic effects, ketamine has emerged as a potential alternative due to its rapid antidepressant action. This systematic review explores the efficacy, safety, and clinical role of ketamine in managing depression among adult cancer patients. Following PRISMA guidelines and PROSPERO registration (CRD42024603120), a comprehensive literature search was conducted across PubMed, MEDLINE, Cochrane CENTRAL, Embase, Web of Science, and PsycINFO. Of 4,256 identified citations, 3,036 unique records remained after removing duplicates. Fourteen studies met the inclusion criteria, comprising randomized controlled trials, cohort studies, and case-control designs. These studies demonstrated that ketamine provides rapid relief from depressive symptoms, often within hours to days, with additional benefits in anxiety, pain, and quality of life. Reported short-term side effects included fatigue, dizziness, and dissociation, while data on long-term safety were limited. Overall, ketamine appears to be a promising short-term treatment option for depression in cancer patients, particularly those with treatment-resistant depression. However, further research is necessary to establish long-term outcomes, optimal dosing strategies, and broader clinical applicability.