Mapping the Use of Ketamine in Treatment-Resistant Depression and Other Psychiatric Disorders: A Scoping Review of Practice Patterns, Efficacy, and Patient Demographic Trends

Background:Ketamine has emerged as a novel treatment for psychiatric disorders, particularly treatment-resistant depression (TRD). Although intravenous (IV) ketamine is not FDA-approved for TRD, esketamine, an FDA-approved therapeutic, has contributed to the widespread clinical use of off-label IV ketamine across the United States. This phenomenon highlights the need for a comprehensive scoping review of current practices.Study Question:What are the current practice patterns, patient demographics, and barriers to accessing ketamine for psychiatric disorders, particularly TRD?Data Sources:The Web of Science, PubMed, CBM, MEDLINE, Cochrane Library, University Theses, and Embase databases were searched from their inception through October 2024 for relevant studies examining ketamine use in psychiatric clinical practice. Studies addressing ketamine use in psychiatry care, provider practices, and patient outcomes were included in the analysis.Study Design:This scoping review mapped the landscape of ketamine utilization in psychiatric care. The review focused on provider utilization patterns (including frequency of ketamine administration, provider roles, and treatment settings), preferred administration methods (IV infusions, intramuscular injections,and other routes), and patient characteristics (age, gender, socioeconomic status, and primary psychiatric diagnoses treated). Key outcomes include provider utilization rates, economic burdens, treatment protocols, and demographic data. Results:Two survey-based studies were included in this review. Intravenous (IV) administration was the most common method of administration reported in both studies, with alternative methods such as intramuscular (IM) and sublingual routes emerging in limited use. Patients receiving ketamine therapy were predominantly middle-aged (36-64 years old), with financial barriers identified as a notable obstacle due to limited insurance coverage and reliance on out-of-pocket payments. Geographic disparities underscored limited access in rural areas, invoking the need for expanded provider networks. Private clinics exhibited greater flexibility in treatment approaches compared to hospital settings, which adhered to standardized protocols. The absence of long-term outcome data and variability in treatment protocols emphasize the need for standardized practices and further research.Conclusion:This scoping review highlights the widespread use of ketamine for TRD, but reveals significant variability in practice patterns and accessibility barriers. Findings emphasize the need for standardized protocols, expanded insurance coverage, and further research to optimize the role of ketamine in psychiatric care.